diff --git a/.github/ISSUE_TEMPLATE/Bug_report.md b/.github/ISSUE_TEMPLATE/Bug_report.md
index a2df8dca..6dfa7d2d 100644
--- a/.github/ISSUE_TEMPLATE/Bug_report.md
+++ b/.github/ISSUE_TEMPLATE/Bug_report.md
@@ -47,7 +47,7 @@ assignees: ''
 
 <!-- Please add an `x` to the respective line. -->
 
-- [ ] latest release version 3.9.0
+- [ ] latest release version 3.9.1
 - [ ] other release - please state the version: ___
 - [ ] the `develop` branch
 
diff --git a/CMakeLists.txt b/CMakeLists.txt
index d5d0ae34..fa77a5ae 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -4,7 +4,7 @@ cmake_minimum_required(VERSION 3.1)
 ## PROJECT
 ## name and version
 ##
-project(nlohmann_json VERSION 3.9.0 LANGUAGES CXX)
+project(nlohmann_json VERSION 3.9.1 LANGUAGES CXX)
 
 ##
 ## INCLUDE
@@ -40,6 +40,7 @@ set(NLOHMANN_JSON_CMAKE_CONFIG_DIR          "${CMAKE_CURRENT_BINARY_DIR}")
 set(NLOHMANN_JSON_CMAKE_VERSION_CONFIG_FILE "${NLOHMANN_JSON_CMAKE_CONFIG_DIR}/${PROJECT_NAME}ConfigVersion.cmake")
 set(NLOHMANN_JSON_CMAKE_PROJECT_CONFIG_FILE "${NLOHMANN_JSON_CMAKE_CONFIG_DIR}/${PROJECT_NAME}Config.cmake")
 set(NLOHMANN_JSON_CMAKE_PROJECT_TARGETS_FILE "${NLOHMANN_JSON_CMAKE_CONFIG_DIR}/${PROJECT_NAME}Targets.cmake")
+set(NLOHMANN_JSON_PKGCONFIG_INSTALL_DIR     "${CMAKE_INSTALL_LIBDIR}/pkgconfig")
 
 if (JSON_MultipleHeaders)
     set(NLOHMANN_JSON_INCLUDE_BUILD_DIR "${PROJECT_SOURCE_DIR}/include/")
@@ -157,7 +158,7 @@ endif()
         DESTINATION ${NLOHMANN_JSON_CONFIG_INSTALL_DIR}
     )
     install(
-        FILES "${CMAKE_BINARY_DIR}/${PROJECT_NAME}.pc"
-        DESTINATION lib/pkgconfig
+        FILES "${CMAKE_CURRENT_BINARY_DIR}/${PROJECT_NAME}.pc"
+        DESTINATION ${NLOHMANN_JSON_PKGCONFIG_INSTALL_DIR}
     )
 endif()
diff --git a/ChangeLog.md b/ChangeLog.md
index 7a762275..e4cec7c5 100644
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -1,6 +1,29 @@
 # Changelog
 All notable changes to this project will be documented in this file. This project adheres to [Semantic Versioning](http://semver.org/).
 
+## [v3.9.1](https://github.com/nlohmann/json/releases/tag/v3.9.1) (2020-08-06)
+
+[Full Changelog](https://github.com/nlohmann/json/compare/v3.9.0...v3.9.1)
+
+- Can't parse not formatted JSON. [\#2340](https://github.com/nlohmann/json/issues/2340)
+- parse returns desired array contained in array when JSON text begins with square bracket on gcc 7.5.0 [\#2339](https://github.com/nlohmann/json/issues/2339)
+- Unexpected deserialization difference between Mac and Linux [\#2338](https://github.com/nlohmann/json/issues/2338)
+- Reading ordered\_json from file causes compile error [\#2331](https://github.com/nlohmann/json/issues/2331)
+- ignore\_comment=true fails on multiple consecutive lines starting with comments [\#2330](https://github.com/nlohmann/json/issues/2330)
+- Update documentation about Homebrew installation and CMake integration - Homebrew [\#2326](https://github.com/nlohmann/json/issues/2326)
+- Chinese character initialize error [\#2325](https://github.com/nlohmann/json/issues/2325)
+- json.update and vector\<pair\>does not work with ordered\_json [\#2315](https://github.com/nlohmann/json/issues/2315)
+- Ambiguous call to overloaded function [\#2210](https://github.com/nlohmann/json/issues/2210)
+
+- Fix fallthrough warning [\#2333](https://github.com/nlohmann/json/pull/2333) ([nlohmann](https://github.com/nlohmann))
+- Fix lexer to properly cope with repeated comments [\#2332](https://github.com/nlohmann/json/pull/2332) ([nlohmann](https://github.com/nlohmann))
+- Fix name of Homebrew formula in documentation [\#2327](https://github.com/nlohmann/json/pull/2327) ([nlohmann](https://github.com/nlohmann))
+- fix typo [\#2320](https://github.com/nlohmann/json/pull/2320) ([wx257osn2](https://github.com/wx257osn2))
+- Fix a bug due to missing overloads in ordered\_map container [\#2319](https://github.com/nlohmann/json/pull/2319) ([nlohmann](https://github.com/nlohmann))
+- cmake: install pkg-config file relative to current\_binary\_dir [\#2318](https://github.com/nlohmann/json/pull/2318) ([eli-schwartz](https://github.com/eli-schwartz))
+- Fixed installation of pkg-config file on other than Ubuntu [\#2314](https://github.com/nlohmann/json/pull/2314) ([xvitaly](https://github.com/xvitaly))
+- Cleanup [\#2303](https://github.com/nlohmann/json/pull/2303) ([nlohmann](https://github.com/nlohmann))
+
 ## [v3.9.0](https://github.com/nlohmann/json/releases/tag/v3.9.0) (2020-07-27)
 
 [Full Changelog](https://github.com/nlohmann/json/compare/v3.8.0...v3.9.0)
@@ -80,7 +103,6 @@ All notable changes to this project will be documented in this file. This projec
 - Fix bug in CBOR tag handling [\#2308](https://github.com/nlohmann/json/pull/2308) ([nlohmann](https://github.com/nlohmann))
 - added inline to NLOHMANN\_DEFINE\_TYPE\_NON\_INTRUSIVE macro [\#2306](https://github.com/nlohmann/json/pull/2306) ([jwittbrodt](https://github.com/jwittbrodt))
 - fixes unused variable 'ex' for \#2304 [\#2305](https://github.com/nlohmann/json/pull/2305) ([AODQ](https://github.com/AODQ))
-- Cleanup [\#2303](https://github.com/nlohmann/json/pull/2303) ([nlohmann](https://github.com/nlohmann))
 - Add test with multiple translation units [\#2301](https://github.com/nlohmann/json/pull/2301) ([nlohmann](https://github.com/nlohmann))
 - Merge GitHub actions [\#2300](https://github.com/nlohmann/json/pull/2300) ([nlohmann](https://github.com/nlohmann))
 - Fix unused parameter [\#2299](https://github.com/nlohmann/json/pull/2299) ([nlohmann](https://github.com/nlohmann))
@@ -741,6 +763,8 @@ All notable changes to this project will be documented in this file. This projec
 - Added to\_string and added basic tests [\#1585](https://github.com/nlohmann/json/pull/1585) ([Macr0Nerd](https://github.com/Macr0Nerd))
 - Regression tests for MSVC [\#1570](https://github.com/nlohmann/json/pull/1570) ([nickaein](https://github.com/nickaein))
 - Fix/1511 [\#1555](https://github.com/nlohmann/json/pull/1555) ([theodelrieu](https://github.com/theodelrieu))
+- Remove C++17 extension warning from clang; \#1535 [\#1551](https://github.com/nlohmann/json/pull/1551) ([heavywatal](https://github.com/heavywatal))
+- moved from Catch to doctest for unit tests [\#1439](https://github.com/nlohmann/json/pull/1439) ([onqtam](https://github.com/onqtam))
 
 ## [v3.6.1](https://github.com/nlohmann/json/releases/tag/v3.6.1) (2019-03-20)
 
@@ -843,7 +867,6 @@ All notable changes to this project will be documented in this file. This projec
 - Implicit type conversion error on MSVC [\#1333](https://github.com/nlohmann/json/issues/1333)
 - NuGet Package [\#1132](https://github.com/nlohmann/json/issues/1132)
 
-- Remove C++17 extension warning from clang; \#1535 [\#1551](https://github.com/nlohmann/json/pull/1551) ([heavywatal](https://github.com/heavywatal))
 - Change macros to numeric\_limits [\#1514](https://github.com/nlohmann/json/pull/1514) ([naszta](https://github.com/naszta))
 - fix GCC 7.1.1 - 7.2.1 on CentOS [\#1496](https://github.com/nlohmann/json/pull/1496) ([lieff](https://github.com/lieff))
 - Update Buckaroo instructions in README.md [\#1495](https://github.com/nlohmann/json/pull/1495) ([njlr](https://github.com/njlr))
@@ -859,7 +882,6 @@ All notable changes to this project will be documented in this file. This projec
 - remove extra semicolon from readme [\#1451](https://github.com/nlohmann/json/pull/1451) ([Afforix](https://github.com/Afforix))
 - attempt to fix \#1445, flush buffer in serializer::dump\_escaped in UTF8\_REJECT case. [\#1446](https://github.com/nlohmann/json/pull/1446) ([scinart](https://github.com/scinart))
 - Use C++11 features supported by CMake 3.1. [\#1441](https://github.com/nlohmann/json/pull/1441) ([iwanders](https://github.com/iwanders))
-- moved from Catch to doctest for unit tests [\#1439](https://github.com/nlohmann/json/pull/1439) ([onqtam](https://github.com/onqtam))
 - :rotating\_light: fixed unused variable warning [\#1435](https://github.com/nlohmann/json/pull/1435) ([pboettch](https://github.com/pboettch))
 - allow push\_back\(\) and pop\_back\(\) calls on json\_pointer [\#1434](https://github.com/nlohmann/json/pull/1434) ([pboettch](https://github.com/pboettch))
 - Add instructions about using nlohmann/json with the conda package manager [\#1430](https://github.com/nlohmann/json/pull/1430) ([nicoddemus](https://github.com/nicoddemus))
@@ -870,6 +892,7 @@ All notable changes to this project will be documented in this file. This projec
 - Fix x64 target platform for appveyor [\#1414](https://github.com/nlohmann/json/pull/1414) ([nickaein](https://github.com/nickaein))
 - Improve dump\_integer performance [\#1411](https://github.com/nlohmann/json/pull/1411) ([nickaein](https://github.com/nickaein))
 - buildsystem: relax requirement on cmake version [\#1409](https://github.com/nlohmann/json/pull/1409) ([yann-morin-1998](https://github.com/yann-morin-1998))
+-  Added Support for Structured Bindings  [\#1391](https://github.com/nlohmann/json/pull/1391) ([pratikpc](https://github.com/pratikpc))
 - CMake: Optional Install if Embedded [\#1330](https://github.com/nlohmann/json/pull/1330) ([ax3l](https://github.com/ax3l))
 
 ## [v3.5.0](https://github.com/nlohmann/json/releases/tag/v3.5.0) (2018-12-21)
@@ -939,7 +962,6 @@ All notable changes to this project will be documented in this file. This projec
 - Check value for existence by json\_pointer [\#1194](https://github.com/nlohmann/json/issues/1194)
 
 - Feature/add file input adapter [\#1392](https://github.com/nlohmann/json/pull/1392) ([dumarjo](https://github.com/dumarjo))
--  Added Support for Structured Bindings  [\#1391](https://github.com/nlohmann/json/pull/1391) ([pratikpc](https://github.com/pratikpc))
 - Link to issue \#958 broken [\#1382](https://github.com/nlohmann/json/pull/1382) ([kjpus](https://github.com/kjpus))
 - readme: fix typo [\#1380](https://github.com/nlohmann/json/pull/1380) ([manu-chroma](https://github.com/manu-chroma))
 - recommend using explicit from JSON conversions [\#1363](https://github.com/nlohmann/json/pull/1363) ([theodelrieu](https://github.com/theodelrieu))
@@ -948,6 +970,7 @@ All notable changes to this project will be documented in this file. This projec
 - Set eofbit on exhausted input stream. [\#1343](https://github.com/nlohmann/json/pull/1343) ([mefyl](https://github.com/mefyl))
 - Add a SFINAE friendly iterator\_traits and use that instead. [\#1342](https://github.com/nlohmann/json/pull/1342) ([dgavedissian](https://github.com/dgavedissian))
 - Fix EOL Whitespaces & CMake Spelling [\#1329](https://github.com/nlohmann/json/pull/1329) ([ax3l](https://github.com/ax3l))
+- Add BSON support [\#1320](https://github.com/nlohmann/json/pull/1320) ([nlohmann](https://github.com/nlohmann))
 
 ## [v3.4.0](https://github.com/nlohmann/json/releases/tag/v3.4.0) (2018-10-30)
 
@@ -987,7 +1010,6 @@ All notable changes to this project will be documented in this file. This projec
 - Soften the landing when dumping non-UTF8 strings \(type\_error.316 exception\) [\#1198](https://github.com/nlohmann/json/issues/1198)
 
 - Add macro to define enum/JSON mapping [\#1323](https://github.com/nlohmann/json/pull/1323) ([nlohmann](https://github.com/nlohmann))
-- Add BSON support [\#1320](https://github.com/nlohmann/json/pull/1320) ([nlohmann](https://github.com/nlohmann))
 - Properly convert constants to CharType [\#1315](https://github.com/nlohmann/json/pull/1315) ([nlohmann](https://github.com/nlohmann))
 - Allow to set error handler for decoding errors [\#1314](https://github.com/nlohmann/json/pull/1314) ([nlohmann](https://github.com/nlohmann))
 - Add Meson related info to README [\#1305](https://github.com/nlohmann/json/pull/1305) ([koponomarenko](https://github.com/koponomarenko))
@@ -1975,6 +1997,7 @@ All notable changes to this project will be documented in this file. This projec
 - Fix usage examples' comments for std::multiset [\#321](https://github.com/nlohmann/json/pull/321) ([vasild](https://github.com/vasild))
 - Include dir relocation [\#318](https://github.com/nlohmann/json/pull/318) ([ChristophJud](https://github.com/ChristophJud))
 - trivial documentation fix [\#313](https://github.com/nlohmann/json/pull/313) ([5tefan](https://github.com/5tefan))
+- unit-constructor1.cpp: Fix floating point truncation warning [\#300](https://github.com/nlohmann/json/pull/300) ([t-b](https://github.com/t-b))
 
 ## [v2.0.5](https://github.com/nlohmann/json/releases/tag/v2.0.5) (2016-09-14)
 
@@ -2007,8 +2030,6 @@ All notable changes to this project will be documented in this file. This projec
 - Incorrect parsing of large int64\_t numbers [\#287](https://github.com/nlohmann/json/issues/287)
 - \[question\]: macro to disable floating point support [\#284](https://github.com/nlohmann/json/issues/284)
 
-- unit-constructor1.cpp: Fix floating point truncation warning [\#300](https://github.com/nlohmann/json/pull/300) ([t-b](https://github.com/t-b))
-
 ## [v2.0.2](https://github.com/nlohmann/json/releases/tag/v2.0.2) (2016-07-31)
 
 [Full Changelog](https://github.com/nlohmann/json/compare/v2.0.1...v2.0.2)
@@ -2085,7 +2106,6 @@ All notable changes to this project will be documented in this file. This projec
 - What is within scope? [\#192](https://github.com/nlohmann/json/issues/192)
 - Bugs in miloyip/nativejson-benchmark: roundtrips [\#187](https://github.com/nlohmann/json/issues/187)
 - Floating point exceptions [\#181](https://github.com/nlohmann/json/issues/181)
-- Integer conversion to unsigned [\#178](https://github.com/nlohmann/json/issues/178)
 - map string string fails to compile [\#176](https://github.com/nlohmann/json/issues/176)
 - In basic\_json::basic\_json\(const CompatibleArrayType& val\), the requirement of CompatibleArrayType is not strict enough. [\#174](https://github.com/nlohmann/json/issues/174)
 - Provide a FAQ [\#163](https://github.com/nlohmann/json/issues/163)
@@ -2104,7 +2124,6 @@ All notable changes to this project will be documented in this file. This projec
 - fixed noexcept; added constexpr [\#208](https://github.com/nlohmann/json/pull/208) ([nlohmann](https://github.com/nlohmann))
 - Add support for afl-fuzz testing [\#207](https://github.com/nlohmann/json/pull/207) ([mykter](https://github.com/mykter))
 - replaced ssize\_t occurrences with auto \(addresses \#204\) [\#205](https://github.com/nlohmann/json/pull/205) ([nlohmann](https://github.com/nlohmann))
-- Fixed issue \#199 - Small bugs in json.hpp \(get\_number\) and unit.cpp \(non-standard integer type test\) [\#200](https://github.com/nlohmann/json/pull/200) ([twelsby](https://github.com/twelsby))
 - Fix broken link [\#197](https://github.com/nlohmann/json/pull/197) ([vog](https://github.com/vog))
 - Issue \#195 - update Travis to Trusty due to gcc/clang strtod\(\) bug [\#196](https://github.com/nlohmann/json/pull/196) ([twelsby](https://github.com/twelsby))
 - Issue \#178 - Extending support to full uint64\_t/int64\_t range and unsigned type \(updated\) [\#193](https://github.com/nlohmann/json/pull/193) ([twelsby](https://github.com/twelsby))
@@ -2118,6 +2137,7 @@ All notable changes to this project will be documented in this file. This projec
 - Floating point equality [\#185](https://github.com/nlohmann/json/issues/185)
 - Unused variables in catch [\#180](https://github.com/nlohmann/json/issues/180)
 - Typo in documentation [\#179](https://github.com/nlohmann/json/issues/179)
+- Integer conversion to unsigned [\#178](https://github.com/nlohmann/json/issues/178)
 - JSON performance benchmark comparision [\#177](https://github.com/nlohmann/json/issues/177)
 - Since re2c is often ignored in pull requests, it may make sense to make a contributing.md file [\#175](https://github.com/nlohmann/json/issues/175)
 - Question about exceptions [\#173](https://github.com/nlohmann/json/issues/173)
@@ -2131,11 +2151,11 @@ All notable changes to this project will be documented in this file. This projec
 - range based for loop for objects [\#83](https://github.com/nlohmann/json/issues/83)
 - Consider submitting this to the Boost Library Incubator [\#66](https://github.com/nlohmann/json/issues/66)
 
+- Fixed issue \#199 - Small bugs in json.hpp \(get\_number\) and unit.cpp \(non-standard integer type test\) [\#200](https://github.com/nlohmann/json/pull/200) ([twelsby](https://github.com/twelsby))
 - Fixed Issue \#186 - add strto\(f|d|ld\) overload wrappers, "-0.0" special case and FP trailing zero [\#191](https://github.com/nlohmann/json/pull/191) ([twelsby](https://github.com/twelsby))
 - Issue \#185 - remove approx\(\) and use \#pragma to kill warnings [\#190](https://github.com/nlohmann/json/pull/190) ([twelsby](https://github.com/twelsby))
 - Fixed Issue \#171 - added two extra template overloads of operator\[\] for T\* arguments [\#189](https://github.com/nlohmann/json/pull/189) ([twelsby](https://github.com/twelsby))
 - Fixed issue \#167 - removed operator ValueType\(\) condition for VS2015 [\#188](https://github.com/nlohmann/json/pull/188) ([twelsby](https://github.com/twelsby))
-- Implementation of get\_ref\(\) [\#184](https://github.com/nlohmann/json/pull/184) ([dariomt](https://github.com/dariomt))
 - Fixed some typos in CONTRIBUTING.md [\#182](https://github.com/nlohmann/json/pull/182) ([nibroc](https://github.com/nibroc))
 
 ## [v1.0.0](https://github.com/nlohmann/json/releases/tag/v1.0.0) (2015-12-27)
@@ -2177,6 +2197,7 @@ All notable changes to this project will be documented in this file. This projec
 - Wishlist [\#65](https://github.com/nlohmann/json/issues/65)
 - Windows/Visual Studio \(through 2013\) is unsupported [\#62](https://github.com/nlohmann/json/issues/62)
 
+- Implementation of get\_ref\(\) [\#184](https://github.com/nlohmann/json/pull/184) ([dariomt](https://github.com/dariomt))
 - Replace sprintf with hex function, this fixes \#149 [\#153](https://github.com/nlohmann/json/pull/153) ([whackashoe](https://github.com/whackashoe))
 - Fix character skipping after a surrogate pair [\#146](https://github.com/nlohmann/json/pull/146) ([robertmrk](https://github.com/robertmrk))
 - Detect correctly pointer-to-const [\#137](https://github.com/nlohmann/json/pull/137) ([dariomt](https://github.com/dariomt))
diff --git a/README.md b/README.md
index 07933a5b..ba257d94 100644
--- a/README.md
+++ b/README.md
@@ -1611,7 +1611,7 @@ Here is a related issue [#1924](https://github.com/nlohmann/json/issues/1924).
 - The code contains numerous debug **assertions** which can be switched off by defining the preprocessor macro `NDEBUG`, see the [documentation of `assert`](https://en.cppreference.com/w/cpp/error/assert). In particular, note [`operator[]`](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_a233b02b0839ef798942dd46157cc0fe6.html#a233b02b0839ef798942dd46157cc0fe6) implements **unchecked access** for const objects: If the given key is not present, the behavior is undefined (think of a dereferenced null pointer) and yields an [assertion failure](https://github.com/nlohmann/json/issues/289) if assertions are switched on. If you are not sure whether an element in an object exists, use checked access with the [`at()` function](https://nlohmann.github.io/json/classnlohmann_1_1basic__json_a73ae333487310e3302135189ce8ff5d8.html#a73ae333487310e3302135189ce8ff5d8). Furthermore, you can define `JSON_ASSERT(x)` to replace calls to `assert(x)`.
 - As the exact type of a number is not defined in the [JSON specification](https://tools.ietf.org/html/rfc8259.html), this library tries to choose the best fitting C++ number type automatically. As a result, the type `double` may be used to store numbers which may yield [**floating-point exceptions**](https://github.com/nlohmann/json/issues/181) in certain rare situations if floating-point exceptions have been unmasked in the calling code. These exceptions are not caused by the library and need to be fixed in the calling code, such as by re-masking the exceptions prior to calling library functions.
 - The code can be compiled without C++ **runtime type identification** features; that is, you can use the `-fno-rtti` compiler flag.
-- **Exceptions** are used widely within the library. They can, however, be switched off with either using the compiler flag `-fno-exceptions` or by defining the symbol `JSON_NOEXCEPTION`. In this case, exceptions are replaced by `abort()` calls. You can further control this behavior by defining `JSON_THROW_USER´` (overriding `throw`), `JSON_TRY_USER` (overriding `try`), and `JSON_CATCH_USER` (overriding `catch`). Note that `JSON_THROW_USER` should leave the current scope (e.g., by throwing or aborting), as continuing after it may yield undefined behavior.
+- **Exceptions** are used widely within the library. They can, however, be switched off with either using the compiler flag `-fno-exceptions` or by defining the symbol `JSON_NOEXCEPTION`. In this case, exceptions are replaced by `abort()` calls. You can further control this behavior by defining `JSON_THROW_USER` (overriding `throw`), `JSON_TRY_USER` (overriding `try`), and `JSON_CATCH_USER` (overriding `catch`). Note that `JSON_THROW_USER` should leave the current scope (e.g., by throwing or aborting), as continuing after it may yield undefined behavior.
 
 ## Execute unit tests
 
diff --git a/doc/Doxyfile b/doc/Doxyfile
index e6207fb0..9884f959 100644
--- a/doc/Doxyfile
+++ b/doc/Doxyfile
@@ -5,7 +5,7 @@
 #---------------------------------------------------------------------------
 DOXYFILE_ENCODING      = UTF-8
 PROJECT_NAME           = "JSON for Modern C++"
-PROJECT_NUMBER         = 3.9.0
+PROJECT_NUMBER         = 3.9.1
 PROJECT_BRIEF          =
 PROJECT_LOGO           =
 OUTPUT_DIRECTORY       = .
diff --git a/doc/examples/README.link b/doc/examples/README.link
index 786b27be..2bb56a02 100644
--- a/doc/examples/README.link
+++ b/doc/examples/README.link
@@ -1 +1 @@
-<a target="_blank" href="https://wandbox.org/permlink/shE8T6phAQiEzAad"><b>online</b></a>
\ No newline at end of file
+<a target="_blank" href="https://wandbox.org/permlink/UYcLkpu1GaaAO2Cp"><b>online</b></a>
\ No newline at end of file
diff --git a/doc/examples/meta.output b/doc/examples/meta.output
index ffadccbe..0fac5b41 100644
--- a/doc/examples/meta.output
+++ b/doc/examples/meta.output
@@ -11,7 +11,7 @@
     "version": {
         "major": 3,
         "minor": 9,
-        "patch": 0,
-        "string": "3.9.0"
+        "patch": 1,
+        "string": "3.9.1"
     }
 }
diff --git a/doc/index.md b/doc/index.md
index e990e7a3..66a13ef2 100644
--- a/doc/index.md
+++ b/doc/index.md
@@ -332,4 +332,4 @@ Note that this table only lists those exceptions thrown due to the type. For ins
 @author [Niels Lohmann](http://nlohmann.me)
 @see https://github.com/nlohmann/json to download the source code
 
-@version 3.9.0
+@version 3.9.1
diff --git a/doc/json.gif b/doc/json.gif
index d3dfb91c..7542048e 100644
Binary files a/doc/json.gif and b/doc/json.gif differ
diff --git a/doc/mkdocs/docs/integration/package_managers.md b/doc/mkdocs/docs/integration/package_managers.md
index 17f2005e..58b3eab5 100644
--- a/doc/mkdocs/docs/integration/package_managers.md
+++ b/doc/mkdocs/docs/integration/package_managers.md
@@ -12,14 +12,14 @@ If you are using OS X and [Homebrew](http://brew.sh), just type
 
 ```sh
 brew tap nlohmann/json
-brew install nlohmann_json
+brew install nlohmann-json
 ```
 
 and you're set. If you want the bleeding edge rather than the latest release, use
 
 ```sh
 brew tap nlohmann/json
-brew install nlohmann_json --HEAD
+brew install nlohmann-json --HEAD
 ```
 
 instead.
@@ -38,19 +38,19 @@ instead.
 
 		```sh
 		brew tap nlohmann/json
-		brew install nlohmann_json
+		brew install nlohmann-json
 		```
 
-	3. Determine the include path, which defaults to `/usr/local/Cellar/nlohmann_json/$version/include`, where `$version` is the version of the library, e.g. `3.7.3`. The path of the library can be determined with
+	3. Determine the include path, which defaults to `/usr/local/Cellar/nlohmann-json/$version/include`, where `$version` is the version of the library, e.g. `3.7.3`. The path of the library can be determined with
 
 		```sh
-		brew list nlohmann_json
+		brew list nlohmann-json
 		```
 
 	4. Compile the code. For instance, the code can be compiled using Clang with
 
 		```sh
-		clang++ example.cpp -I/usr/local/Cellar/nlohmann_json/3.7.3/include -std=c++11 -o example
+		clang++ example.cpp -I/usr/local/Cellar/nlohmann-json/3.7.3/include -std=c++11 -o example
 		```
 
 ## Meson
diff --git a/include/nlohmann/detail/input/lexer.hpp b/include/nlohmann/detail/input/lexer.hpp
index 60eb3526..0a960135 100644
--- a/include/nlohmann/detail/input/lexer.hpp
+++ b/include/nlohmann/detail/input/lexer.hpp
@@ -880,13 +880,13 @@ class lexer : public lexer_base<BasicJsonType>
                                 default:
                                 {
                                     unget();
-                                    break;
+                                    continue;
                                 }
                             }
                         }
 
                         default:
-                            break;
+                            continue;
                     }
                 }
             }
@@ -1511,7 +1511,7 @@ scan_number_done:
         skip_whitespace();
 
         // ignore comments
-        if (ignore_comments && current == '/')
+        while (ignore_comments && current == '/')
         {
             if (!scan_comment())
             {
diff --git a/include/nlohmann/json.hpp b/include/nlohmann/json.hpp
index 3b122b0c..a9e6c76d 100644
--- a/include/nlohmann/json.hpp
+++ b/include/nlohmann/json.hpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
@@ -32,7 +32,7 @@ SOFTWARE.
 
 #define NLOHMANN_JSON_VERSION_MAJOR 3
 #define NLOHMANN_JSON_VERSION_MINOR 9
-#define NLOHMANN_JSON_VERSION_PATCH 0
+#define NLOHMANN_JSON_VERSION_PATCH 1
 
 #include <algorithm> // all_of, find, for_each
 #include <cstddef> // nullptr_t, ptrdiff_t, size_t
@@ -1052,7 +1052,7 @@ class basic_json
                     object = nullptr;  // silence warning, see #821
                     if (JSON_HEDLEY_UNLIKELY(t == value_t::null))
                     {
-                        JSON_THROW(other_error::create(500, "961c151d2e87f2686a955a9be24d316f1362bf21 3.9.0")); // LCOV_EXCL_LINE
+                        JSON_THROW(other_error::create(500, "961c151d2e87f2686a955a9be24d316f1362bf21 3.9.1")); // LCOV_EXCL_LINE
                     }
                     break;
                 }
diff --git a/include/nlohmann/ordered_map.hpp b/include/nlohmann/ordered_map.hpp
index 2a72fefd..57679091 100644
--- a/include/nlohmann/ordered_map.hpp
+++ b/include/nlohmann/ordered_map.hpp
@@ -18,6 +18,7 @@ template <class Key, class T, class IgnoredLess = std::less<Key>,
     using mapped_type = T;
     using Container = std::vector<std::pair<const Key, T>, Allocator>;
     using typename Container::iterator;
+    using typename Container::const_iterator;
     using typename Container::size_type;
     using typename Container::value_type;
 
@@ -30,7 +31,7 @@ template <class Key, class T, class IgnoredLess = std::less<Key>,
     ordered_map(std::initializer_list<T> init, const Allocator& alloc = Allocator() )
         : Container{init, alloc} {}
 
-    std::pair<iterator, bool> emplace(key_type&& key, T&& t)
+    std::pair<iterator, bool> emplace(const key_type& key, T&& t)
     {
         for (auto it = this->begin(); it != this->end(); ++it)
         {
@@ -43,9 +44,40 @@ template <class Key, class T, class IgnoredLess = std::less<Key>,
         return {--this->end(), true};
     }
 
-    T& operator[](Key&& key)
+    T& operator[](const Key& key)
     {
-        return emplace(std::move(key), T{}).first->second;
+        return emplace(key, T{}).first->second;
+    }
+
+    const T& operator[](const Key& key) const
+    {
+        return at(key);
+    }
+
+    T& at(const Key& key)
+    {
+        for (auto it = this->begin(); it != this->end(); ++it)
+        {
+            if (it->first == key)
+            {
+                return it->second;
+            }
+        }
+
+        throw std::out_of_range("key not found");
+    }
+
+    const T& at(const Key& key) const
+    {
+        for (auto it = this->begin(); it != this->end(); ++it)
+        {
+            if (it->first == key)
+            {
+                return it->second;
+            }
+        }
+
+        throw std::out_of_range("key not found");
     }
 
     size_type erase(const Key& key)
@@ -66,6 +98,74 @@ template <class Key, class T, class IgnoredLess = std::less<Key>,
         }
         return 0;
     }
+
+    iterator erase(iterator pos)
+    {
+        auto it = pos;
+
+        // Since we cannot move const Keys, re-construct them in place
+        for (auto next = it; ++next != this->end(); ++it)
+        {
+            it->~value_type(); // Destroy but keep allocation
+            new (&*it) value_type{std::move(*next)};
+        }
+        Container::pop_back();
+        return pos;
+    }
+
+    size_type count(const Key& key) const
+    {
+        for (auto it = this->begin(); it != this->end(); ++it)
+        {
+            if (it->first == key)
+            {
+                return 1;
+            }
+        }
+        return 0;
+    }
+
+    iterator find(const Key& key)
+    {
+        for (auto it = this->begin(); it != this->end(); ++it)
+        {
+            if (it->first == key)
+            {
+                return it;
+            }
+        }
+        return Container::end();
+    }
+
+    const_iterator find(const Key& key) const
+    {
+        for (auto it = this->begin(); it != this->end(); ++it)
+        {
+            if (it->first == key)
+            {
+                return it;
+            }
+        }
+        return Container::end();
+    }
+
+    std::pair<iterator, bool> insert( value_type&& value )
+    {
+        return emplace(value.first, std::move(value.second));
+    }
+
+    std::pair<iterator, bool> insert( const value_type& value )
+    {
+        for (auto it = this->begin(); it != this->end(); ++it)
+        {
+            if (it->first == value.first)
+            {
+                return {it, false};
+            }
+        }
+        Container::push_back(value);
+        return {--this->end(), true};
+    }
 };
 
 }  // namespace nlohmann
diff --git a/meson.build b/meson.build
index 6f95c9b6..c7b2cb41 100644
--- a/meson.build
+++ b/meson.build
@@ -1,6 +1,6 @@
 project('nlohmann_json',
     'cpp',
-    version : '3.9.0',
+    version : '3.9.1',
     license : 'MIT',
 )
 
diff --git a/single_include/nlohmann/json.hpp b/single_include/nlohmann/json.hpp
index 6a0f47ab..a70aaf8c 100644
--- a/single_include/nlohmann/json.hpp
+++ b/single_include/nlohmann/json.hpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
@@ -32,7 +32,7 @@ SOFTWARE.
 
 #define NLOHMANN_JSON_VERSION_MAJOR 3
 #define NLOHMANN_JSON_VERSION_MINOR 9
-#define NLOHMANN_JSON_VERSION_PATCH 0
+#define NLOHMANN_JSON_VERSION_PATCH 1
 
 #include <algorithm> // all_of, find, for_each
 #include <cstddef> // nullptr_t, ptrdiff_t, size_t
@@ -6759,13 +6759,13 @@ class lexer : public lexer_base<BasicJsonType>
                                 default:
                                 {
                                     unget();
-                                    break;
+                                    continue;
                                 }
                             }
                         }
 
                         default:
-                            break;
+                            continue;
                     }
                 }
             }
@@ -7390,7 +7390,7 @@ scan_number_done:
         skip_whitespace();
 
         // ignore comments
-        if (ignore_comments && current == '/')
+        while (ignore_comments && current == '/')
         {
             if (!scan_comment())
             {
@@ -16408,6 +16408,7 @@ template <class Key, class T, class IgnoredLess = std::less<Key>,
     using mapped_type = T;
     using Container = std::vector<std::pair<const Key, T>, Allocator>;
     using typename Container::iterator;
+    using typename Container::const_iterator;
     using typename Container::size_type;
     using typename Container::value_type;
 
@@ -16420,7 +16421,7 @@ template <class Key, class T, class IgnoredLess = std::less<Key>,
     ordered_map(std::initializer_list<T> init, const Allocator& alloc = Allocator() )
         : Container{init, alloc} {}
 
-    std::pair<iterator, bool> emplace(key_type&& key, T&& t)
+    std::pair<iterator, bool> emplace(const key_type& key, T&& t)
     {
         for (auto it = this->begin(); it != this->end(); ++it)
         {
@@ -16433,9 +16434,40 @@ template <class Key, class T, class IgnoredLess = std::less<Key>,
         return {--this->end(), true};
     }
 
-    T& operator[](Key&& key)
+    T& operator[](const Key& key)
     {
-        return emplace(std::move(key), T{}).first->second;
+        return emplace(key, T{}).first->second;
+    }
+
+    const T& operator[](const Key& key) const
+    {
+        return at(key);
+    }
+
+    T& at(const Key& key)
+    {
+        for (auto it = this->begin(); it != this->end(); ++it)
+        {
+            if (it->first == key)
+            {
+                return it->second;
+            }
+        }
+
+        throw std::out_of_range("key not found");
+    }
+
+    const T& at(const Key& key) const
+    {
+        for (auto it = this->begin(); it != this->end(); ++it)
+        {
+            if (it->first == key)
+            {
+                return it->second;
+            }
+        }
+
+        throw std::out_of_range("key not found");
     }
 
     size_type erase(const Key& key)
@@ -16456,6 +16488,74 @@ template <class Key, class T, class IgnoredLess = std::less<Key>,
         }
         return 0;
     }
+
+    iterator erase(iterator pos)
+    {
+        auto it = pos;
+
+        // Since we cannot move const Keys, re-construct them in place
+        for (auto next = it; ++next != this->end(); ++it)
+        {
+            it->~value_type(); // Destroy but keep allocation
+            new (&*it) value_type{std::move(*next)};
+        }
+        Container::pop_back();
+        return pos;
+    }
+
+    size_type count(const Key& key) const
+    {
+        for (auto it = this->begin(); it != this->end(); ++it)
+        {
+            if (it->first == key)
+            {
+                return 1;
+            }
+        }
+        return 0;
+    }
+
+    iterator find(const Key& key)
+    {
+        for (auto it = this->begin(); it != this->end(); ++it)
+        {
+            if (it->first == key)
+            {
+                return it;
+            }
+        }
+        return Container::end();
+    }
+
+    const_iterator find(const Key& key) const
+    {
+        for (auto it = this->begin(); it != this->end(); ++it)
+        {
+            if (it->first == key)
+            {
+                return it;
+            }
+        }
+        return Container::end();
+    }
+
+    std::pair<iterator, bool> insert( value_type&& value )
+    {
+        return emplace(value.first, std::move(value.second));
+    }
+
+    std::pair<iterator, bool> insert( const value_type& value )
+    {
+        for (auto it = this->begin(); it != this->end(); ++it)
+        {
+            if (it->first == value.first)
+            {
+                return {it, false};
+            }
+        }
+        Container::push_back(value);
+        return {--this->end(), true};
+    }
 };
 
 }  // namespace nlohmann
@@ -17440,7 +17540,7 @@ class basic_json
                     object = nullptr;  // silence warning, see #821
                     if (JSON_HEDLEY_UNLIKELY(t == value_t::null))
                     {
-                        JSON_THROW(other_error::create(500, "961c151d2e87f2686a955a9be24d316f1362bf21 3.9.0")); // LCOV_EXCL_LINE
+                        JSON_THROW(other_error::create(500, "961c151d2e87f2686a955a9be24d316f1362bf21 3.9.1")); // LCOV_EXCL_LINE
                     }
                     break;
                 }
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 76ba31d8..3d8bceb7 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -126,10 +126,12 @@ set(files
     src/unit-msgpack.cpp
     src/unit-noexcept.cpp
     src/unit-ordered_json.cpp
+    src/unit-ordered_map.cpp
     src/unit-pointer_access.cpp
     src/unit-readme.cpp
     src/unit-reference_access.cpp
-    src/unit-regression.cpp
+    src/unit-regression1.cpp
+    src/unit-regression2.cpp
     src/unit-serialization.cpp
     src/unit-testsuites.cpp
     src/unit-to_chars.cpp
diff --git a/test/src/fuzzer-driver_afl.cpp b/test/src/fuzzer-driver_afl.cpp
index a9368ca9..06ac3af9 100644
--- a/test/src/fuzzer-driver_afl.cpp
+++ b/test/src/fuzzer-driver_afl.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (fuzz test support)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 This file implements a driver for American Fuzzy Lop (afl-fuzz). It relies on
diff --git a/test/src/fuzzer-parse_bson.cpp b/test/src/fuzzer-parse_bson.cpp
index 1d26a776..8ebb1f10 100644
--- a/test/src/fuzzer-parse_bson.cpp
+++ b/test/src/fuzzer-parse_bson.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (fuzz test support)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 This file implements a parser test suitable for fuzz testing. Given a byte
diff --git a/test/src/fuzzer-parse_cbor.cpp b/test/src/fuzzer-parse_cbor.cpp
index 7d312306..8f2e5969 100644
--- a/test/src/fuzzer-parse_cbor.cpp
+++ b/test/src/fuzzer-parse_cbor.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (fuzz test support)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 This file implements a parser test suitable for fuzz testing. Given a byte
diff --git a/test/src/fuzzer-parse_json.cpp b/test/src/fuzzer-parse_json.cpp
index 4bc54bab..803152d0 100644
--- a/test/src/fuzzer-parse_json.cpp
+++ b/test/src/fuzzer-parse_json.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (fuzz test support)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 This file implements a parser test suitable for fuzz testing. Given a byte
diff --git a/test/src/fuzzer-parse_msgpack.cpp b/test/src/fuzzer-parse_msgpack.cpp
index 8d17b5d9..32366c2a 100644
--- a/test/src/fuzzer-parse_msgpack.cpp
+++ b/test/src/fuzzer-parse_msgpack.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (fuzz test support)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 This file implements a parser test suitable for fuzz testing. Given a byte
diff --git a/test/src/fuzzer-parse_ubjson.cpp b/test/src/fuzzer-parse_ubjson.cpp
index 3d99abbe..4ec69c32 100644
--- a/test/src/fuzzer-parse_ubjson.cpp
+++ b/test/src/fuzzer-parse_ubjson.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (fuzz test support)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 This file implements a parser test suitable for fuzz testing. Given a byte
diff --git a/test/src/unit-algorithms.cpp b/test/src/unit-algorithms.cpp
index d59c090c..c08e858a 100644
--- a/test/src/unit-algorithms.cpp
+++ b/test/src/unit-algorithms.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-allocator.cpp b/test/src/unit-allocator.cpp
index 58f4c63a..40361ce0 100644
--- a/test/src/unit-allocator.cpp
+++ b/test/src/unit-allocator.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-alt-string.cpp b/test/src/unit-alt-string.cpp
index d5131040..b51a5a91 100644
--- a/test/src/unit-alt-string.cpp
+++ b/test/src/unit-alt-string.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-assert_macro.cpp b/test/src/unit-assert_macro.cpp
index b2a71be9..826638fe 100644
--- a/test/src/unit-assert_macro.cpp
+++ b/test/src/unit-assert_macro.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-bson.cpp b/test/src/unit-bson.cpp
index 42dae1f2..6b2e76da 100644
--- a/test/src/unit-bson.cpp
+++ b/test/src/unit-bson.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-capacity.cpp b/test/src/unit-capacity.cpp
index cbe0d6b0..9be901bf 100644
--- a/test/src/unit-capacity.cpp
+++ b/test/src/unit-capacity.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-cbor.cpp b/test/src/unit-cbor.cpp
index 0a8dbf6f..ca4b781a 100644
--- a/test/src/unit-cbor.cpp
+++ b/test/src/unit-cbor.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-class_const_iterator.cpp b/test/src/unit-class_const_iterator.cpp
index f75c4831..608e6a54 100644
--- a/test/src/unit-class_const_iterator.cpp
+++ b/test/src/unit-class_const_iterator.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-class_iterator.cpp b/test/src/unit-class_iterator.cpp
index 0a85e7ad..c06ef0a4 100644
--- a/test/src/unit-class_iterator.cpp
+++ b/test/src/unit-class_iterator.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-class_lexer.cpp b/test/src/unit-class_lexer.cpp
index 0f544d55..15b390cf 100644
--- a/test/src/unit-class_lexer.cpp
+++ b/test/src/unit-class_lexer.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
@@ -241,5 +241,8 @@ TEST_CASE("lexer class")
         CHECK((scan_string("/* true */", true) == json::lexer::token_type::end_of_input));
         CHECK((scan_string("/*/**/", true) == json::lexer::token_type::end_of_input));
         CHECK((scan_string("/*/* */", true) == json::lexer::token_type::end_of_input));
+
+        CHECK((scan_string("//\n//\n", true) == json::lexer::token_type::end_of_input));
+        CHECK((scan_string("/**//**//**/", true) == json::lexer::token_type::end_of_input));
     }
 }
diff --git a/test/src/unit-class_parser.cpp b/test/src/unit-class_parser.cpp
index 2c93a753..07044ed5 100644
--- a/test/src/unit-class_parser.cpp
+++ b/test/src/unit-class_parser.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-comparison.cpp b/test/src/unit-comparison.cpp
index b0984a5b..e375feca 100644
--- a/test/src/unit-comparison.cpp
+++ b/test/src/unit-comparison.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-concepts.cpp b/test/src/unit-concepts.cpp
index 49f2f865..deffc9a4 100644
--- a/test/src/unit-concepts.cpp
+++ b/test/src/unit-concepts.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-constructor1.cpp b/test/src/unit-constructor1.cpp
index 70f52fd2..33bd92c3 100644
--- a/test/src/unit-constructor1.cpp
+++ b/test/src/unit-constructor1.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-constructor2.cpp b/test/src/unit-constructor2.cpp
index a7bf0e50..27f4dfdc 100644
--- a/test/src/unit-constructor2.cpp
+++ b/test/src/unit-constructor2.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-convenience.cpp b/test/src/unit-convenience.cpp
index 41955b3f..162ad56d 100644
--- a/test/src/unit-convenience.cpp
+++ b/test/src/unit-convenience.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-conversions.cpp b/test/src/unit-conversions.cpp
index 32e15ace..de8040c8 100644
--- a/test/src/unit-conversions.cpp
+++ b/test/src/unit-conversions.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-deserialization.cpp b/test/src/unit-deserialization.cpp
index 66556617..716564c0 100644
--- a/test/src/unit-deserialization.cpp
+++ b/test/src/unit-deserialization.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-element_access1.cpp b/test/src/unit-element_access1.cpp
index a619b249..e3f06302 100644
--- a/test/src/unit-element_access1.cpp
+++ b/test/src/unit-element_access1.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-element_access2.cpp b/test/src/unit-element_access2.cpp
index 4abf3dba..18fc6a20 100644
--- a/test/src/unit-element_access2.cpp
+++ b/test/src/unit-element_access2.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-hash.cpp b/test/src/unit-hash.cpp
index ea35300f..b74990d7 100644
--- a/test/src/unit-hash.cpp
+++ b/test/src/unit-hash.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-inspection.cpp b/test/src/unit-inspection.cpp
index 02502e07..004f14d1 100644
--- a/test/src/unit-inspection.cpp
+++ b/test/src/unit-inspection.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-items.cpp b/test/src/unit-items.cpp
index a3f808b2..10621ce7 100644
--- a/test/src/unit-items.cpp
+++ b/test/src/unit-items.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-iterators1.cpp b/test/src/unit-iterators1.cpp
index d389b9f6..45a84a07 100644
--- a/test/src/unit-iterators1.cpp
+++ b/test/src/unit-iterators1.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-iterators2.cpp b/test/src/unit-iterators2.cpp
index c3378e0d..85eb7beb 100644
--- a/test/src/unit-iterators2.cpp
+++ b/test/src/unit-iterators2.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-json_patch.cpp b/test/src/unit-json_patch.cpp
index 23f59b0f..2ad7aadb 100644
--- a/test/src/unit-json_patch.cpp
+++ b/test/src/unit-json_patch.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-json_pointer.cpp b/test/src/unit-json_pointer.cpp
index 7d320bcc..61b6e323 100644
--- a/test/src/unit-json_pointer.cpp
+++ b/test/src/unit-json_pointer.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-large_json.cpp b/test/src/unit-large_json.cpp
index 175b0cd6..600a9915 100644
--- a/test/src/unit-large_json.cpp
+++ b/test/src/unit-large_json.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-merge_patch.cpp b/test/src/unit-merge_patch.cpp
index c664f8f3..34551c75 100644
--- a/test/src/unit-merge_patch.cpp
+++ b/test/src/unit-merge_patch.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-meta.cpp b/test/src/unit-meta.cpp
index 48ef35c1..50dd6b4b 100644
--- a/test/src/unit-meta.cpp
+++ b/test/src/unit-meta.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
@@ -43,10 +43,10 @@ TEST_CASE("version information")
         CHECK(j["url"] == "https://github.com/nlohmann/json");
         CHECK(j["version"] == json(
         {
-            {"string", "3.9.0"},
+            {"string", "3.9.1"},
             {"major", 3},
             {"minor", 9},
-            {"patch", 0}
+            {"patch", 1}
         }));
 
         CHECK(j.find("platform") != j.end());
diff --git a/test/src/unit-modifiers.cpp b/test/src/unit-modifiers.cpp
index 4f5b5729..d66621d8 100644
--- a/test/src/unit-modifiers.cpp
+++ b/test/src/unit-modifiers.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-msgpack.cpp b/test/src/unit-msgpack.cpp
index 42089555..e49a4203 100644
--- a/test/src/unit-msgpack.cpp
+++ b/test/src/unit-msgpack.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-noexcept.cpp b/test/src/unit-noexcept.cpp
index 4ed0f709..7e657bf9 100644
--- a/test/src/unit-noexcept.cpp
+++ b/test/src/unit-noexcept.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-ordered_json.cpp b/test/src/unit-ordered_json.cpp
index 0c8e7154..9b242c82 100644
--- a/test/src/unit-ordered_json.cpp
+++ b/test/src/unit-ordered_json.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-ordered_map.cpp b/test/src/unit-ordered_map.cpp
new file mode 100644
index 00000000..645183d8
--- /dev/null
+++ b/test/src/unit-ordered_map.cpp
@@ -0,0 +1,292 @@
+/*
+    __ _____ _____ _____
+ __|  |   __|     |   | |  JSON for Modern C++ (test suite)
+|  |  |__   |  |  | | | |  version 3.9.1
+|_____|_____|_____|_|___|  https://github.com/nlohmann/json
+
+Licensed under the MIT License <http://opensource.org/licenses/MIT>.
+SPDX-License-Identifier: MIT
+Copyright (c) 2013-2019 Niels Lohmann <http://nlohmann.me>.
+
+Permission is hereby  granted, free of charge, to any  person obtaining a copy
+of this software and associated  documentation files (the "Software"), to deal
+in the Software  without restriction, including without  limitation the rights
+to  use, copy,  modify, merge,  publish, distribute,  sublicense, and/or  sell
+copies  of  the Software,  and  to  permit persons  to  whom  the Software  is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE  IS PROVIDED "AS  IS", WITHOUT WARRANTY  OF ANY KIND,  EXPRESS OR
+IMPLIED,  INCLUDING BUT  NOT  LIMITED TO  THE  WARRANTIES OF  MERCHANTABILITY,
+FITNESS FOR  A PARTICULAR PURPOSE AND  NONINFRINGEMENT. IN NO EVENT  SHALL THE
+AUTHORS  OR COPYRIGHT  HOLDERS  BE  LIABLE FOR  ANY  CLAIM,  DAMAGES OR  OTHER
+LIABILITY, WHETHER IN AN ACTION OF  CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE  OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
+#include "doctest_compatibility.h"
+
+#include <nlohmann/json.hpp>
+using nlohmann::ordered_map;
+
+
+TEST_CASE("ordered_map")
+{
+    SECTION("constructor")
+    {
+        SECTION("constructor from iterator range")
+        {
+            std::map<std::string, std::string> m {{"eins", "one"}, {"zwei", "two"}, {"drei", "three"}};
+            ordered_map<std::string, std::string> om(m.begin(), m.end());
+            CHECK(om.size() == 3);
+        }
+
+        SECTION("copy assignment")
+        {
+            std::map<std::string, std::string> m {{"eins", "one"}, {"zwei", "two"}, {"drei", "three"}};
+            ordered_map<std::string, std::string> om(m.begin(), m.end());
+            const auto com = om;
+            CHECK(com.size() == 3);
+        }
+    }
+
+    SECTION("at")
+    {
+        std::map<std::string, std::string> m {{"eins", "one"}, {"zwei", "two"}, {"drei", "three"}};
+        ordered_map<std::string, std::string> om(m.begin(), m.end());
+        const auto com = om;
+
+        SECTION("with Key&&")
+        {
+            CHECK(om.at(std::string("eins")) == std::string("one"));
+            CHECK(com.at(std::string("eins")) == std::string("one"));
+            CHECK_THROWS_AS(om.at(std::string("vier")), std::out_of_range);
+            CHECK_THROWS_AS(com.at(std::string("vier")), std::out_of_range);
+        }
+
+        SECTION("with const Key&&")
+        {
+            const std::string eins = "eins";
+            const std::string vier = "vier";
+            CHECK(om.at(eins) == std::string("one"));
+            CHECK(com.at(eins) == std::string("one"));
+            CHECK_THROWS_AS(om.at(vier), std::out_of_range);
+            CHECK_THROWS_AS(com.at(vier), std::out_of_range);
+        }
+
+        SECTION("with string literal")
+        {
+            CHECK(om.at("eins") == std::string("one"));
+            CHECK(com.at("eins") == std::string("one"));
+            CHECK_THROWS_AS(om.at("vier"), std::out_of_range);
+            CHECK_THROWS_AS(com.at("vier"), std::out_of_range);
+        }
+    }
+
+    SECTION("operator[]")
+    {
+        std::map<std::string, std::string> m {{"eins", "one"}, {"zwei", "two"}, {"drei", "three"}};
+        ordered_map<std::string, std::string> om(m.begin(), m.end());
+        const auto com = om;
+
+        SECTION("with Key&&")
+        {
+            CHECK(om[std::string("eins")] == std::string("one"));
+            CHECK(com[std::string("eins")] == std::string("one"));
+
+            CHECK(om[std::string("vier")] == std::string(""));
+            CHECK(om.size() == 4);
+        }
+
+        SECTION("with const Key&&")
+        {
+            const std::string eins = "eins";
+            const std::string vier = "vier";
+
+            CHECK(om[eins] == std::string("one"));
+            CHECK(com[eins] == std::string("one"));
+
+            CHECK(om[vier] == std::string(""));
+            CHECK(om.size() == 4);
+        }
+
+        SECTION("with string literal")
+        {
+            CHECK(om["eins"] == std::string("one"));
+            CHECK(com["eins"] == std::string("one"));
+
+            CHECK(om["vier"] == std::string(""));
+            CHECK(om.size() == 4);
+        }
+    }
+
+    SECTION("erase")
+    {
+        ordered_map<std::string, std::string> om;
+        om["eins"] = "one";
+        om["zwei"] = "two";
+        om["drei"] = "three";
+
+        {
+            auto it = om.begin();
+            CHECK(it->first == "eins");
+            ++it;
+            CHECK(it->first == "zwei");
+            ++it;
+            CHECK(it->first == "drei");
+            ++it;
+            CHECK(it == om.end());
+        }
+
+        SECTION("with Key&&")
+        {
+            CHECK(om.size() == 3);
+            CHECK(om.erase(std::string("eins")) == 1);
+            CHECK(om.size() == 2);
+            CHECK(om.erase(std::string("vier")) == 0);
+            CHECK(om.size() == 2);
+
+            auto it = om.begin();
+            CHECK(it->first == "zwei");
+            ++it;
+            CHECK(it->first == "drei");
+            ++it;
+            CHECK(it == om.end());
+        }
+
+        SECTION("with const Key&&")
+        {
+            const std::string eins = "eins";
+            const std::string vier = "vier";
+            CHECK(om.size() == 3);
+            CHECK(om.erase(eins) == 1);
+            CHECK(om.size() == 2);
+            CHECK(om.erase(vier) == 0);
+            CHECK(om.size() == 2);
+
+            auto it = om.begin();
+            CHECK(it->first == "zwei");
+            ++it;
+            CHECK(it->first == "drei");
+            ++it;
+            CHECK(it == om.end());
+        }
+
+        SECTION("with string literal")
+        {
+            CHECK(om.size() == 3);
+            CHECK(om.erase("eins") == 1);
+            CHECK(om.size() == 2);
+            CHECK(om.erase("vier") == 0);
+            CHECK(om.size() == 2);
+
+            auto it = om.begin();
+            CHECK(it->first == "zwei");
+            ++it;
+            CHECK(it->first == "drei");
+            ++it;
+            CHECK(it == om.end());
+        }
+
+        SECTION("with iterator")
+        {
+            CHECK(om.size() == 3);
+            CHECK(om.begin()->first == "eins");
+            CHECK(std::next(om.begin(), 1)->first == "zwei");
+            CHECK(std::next(om.begin(), 2)->first == "drei");
+
+            auto it = om.erase(om.begin());
+            CHECK(it->first == "zwei");
+            CHECK(om.size() == 2);
+
+            auto it2 = om.begin();
+            CHECK(it2->first == "zwei");
+            ++it2;
+            CHECK(it2->first == "drei");
+            ++it2;
+            CHECK(it2 == om.end());
+        }
+    }
+
+    SECTION("count")
+    {
+        ordered_map<std::string, std::string> om;
+        om["eins"] = "one";
+        om["zwei"] = "two";
+        om["drei"] = "three";
+
+        const std::string eins("eins");
+        const std::string vier("vier");
+        CHECK(om.count("eins") == 1);
+        CHECK(om.count(std::string("eins")) == 1);
+        CHECK(om.count(eins) == 1);
+        CHECK(om.count("vier") == 0);
+        CHECK(om.count(std::string("vier")) == 0);
+        CHECK(om.count(vier) == 0);
+    }
+
+    SECTION("find")
+    {
+        ordered_map<std::string, std::string> om;
+        om["eins"] = "one";
+        om["zwei"] = "two";
+        om["drei"] = "three";
+        const auto com = om;
+
+        const std::string eins("eins");
+        const std::string vier("vier");
+        CHECK(om.find("eins") == om.begin());
+        CHECK(om.find(std::string("eins")) == om.begin());
+        CHECK(om.find(eins) == om.begin());
+        CHECK(om.find("vier") == om.end());
+        CHECK(om.find(std::string("vier")) == om.end());
+        CHECK(om.find(vier) == om.end());
+
+        CHECK(com.find("eins") == com.begin());
+        CHECK(com.find(std::string("eins")) == com.begin());
+        CHECK(com.find(eins) == com.begin());
+        CHECK(com.find("vier") == com.end());
+        CHECK(com.find(std::string("vier")) == com.end());
+        CHECK(com.find(vier) == com.end());
+    }
+
+    SECTION("insert")
+    {
+        ordered_map<std::string, std::string> om;
+        om["eins"] = "one";
+        om["zwei"] = "two";
+        om["drei"] = "three";
+
+        SECTION("const value_type&")
+        {
+            ordered_map<std::string, std::string>::value_type vt1 {"eins", "1"};
+            ordered_map<std::string, std::string>::value_type vt4 {"vier", "four"};
+
+            auto res1 = om.insert(vt1);
+            CHECK(res1.first == om.begin());
+            CHECK(res1.second == false);
+            CHECK(om.size() == 3);
+
+            auto res4 = om.insert(vt4);
+            CHECK(res4.first == om.begin() + 3);
+            CHECK(res4.second == true);
+            CHECK(om.size() == 4);
+        }
+
+        SECTION("value_type&&")
+        {
+            auto res1 = om.insert({"eins", "1"});
+            CHECK(res1.first == om.begin());
+            CHECK(res1.second == false);
+            CHECK(om.size() == 3);
+
+            auto res4 = om.insert({"vier", "four"});
+            CHECK(res4.first == om.begin() + 3);
+            CHECK(res4.second == true);
+            CHECK(om.size() == 4);
+        }
+    }
+}
diff --git a/test/src/unit-pointer_access.cpp b/test/src/unit-pointer_access.cpp
index c353c17c..95478b2c 100644
--- a/test/src/unit-pointer_access.cpp
+++ b/test/src/unit-pointer_access.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-readme.cpp b/test/src/unit-readme.cpp
index 729ee954..ed2a4dce 100644
--- a/test/src/unit-readme.cpp
+++ b/test/src/unit-readme.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-reference_access.cpp b/test/src/unit-reference_access.cpp
index 9cbc7aea..c9836776 100644
--- a/test/src/unit-reference_access.cpp
+++ b/test/src/unit-reference_access.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-regression.cpp b/test/src/unit-regression1.cpp
similarity index 81%
rename from test/src/unit-regression.cpp
rename to test/src/unit-regression1.cpp
index 223466a4..18820d17 100644
--- a/test/src/unit-regression.cpp
+++ b/test/src/unit-regression1.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
@@ -128,83 +128,9 @@ struct nocopy
         j = {{"val", n.val}};
     }
 };
-
-struct Data
-{
-    Data() = default;
-    Data(const std::string& a_, const std::string b_) : a(a_), b(b_) {}
-    std::string a {};
-    std::string b {};
-};
-
-void from_json(const json& j, Data& data)
-{
-    j["a"].get_to(data.a);
-    j["b"].get_to(data.b);
 }
 
-bool operator==(Data const& lhs, Data const& rhs)
-{
-    return lhs.a == rhs.a && lhs.b == rhs.b;
-}
-
-//bool operator!=(Data const& lhs, Data const& rhs)
-//{
-//    return !(lhs == rhs);
-//}
-}
-
-/////////////////////////////////////////////////////////////////////
-// for #1021
-/////////////////////////////////////////////////////////////////////
-
-using float_json = nlohmann::basic_json<std::map, std::vector, std::string, bool, std::int64_t, std::uint64_t, float>;
-
-/////////////////////////////////////////////////////////////////////
-// for #1647
-/////////////////////////////////////////////////////////////////////
-namespace
-{
-struct NonDefaultFromJsonStruct { };
-
-inline bool operator== (NonDefaultFromJsonStruct const&, NonDefaultFromJsonStruct const&)
-{
-    return true;
-}
-
-enum class for_1647 { one, two };
-
-NLOHMANN_JSON_SERIALIZE_ENUM(for_1647,
-{
-    {for_1647::one, "one"},
-    {for_1647::two, "two"},
-})
-}
-
-namespace nlohmann
-{
-template <>
-struct adl_serializer<NonDefaultFromJsonStruct>
-{
-    static NonDefaultFromJsonStruct from_json (json const&) noexcept
-    {
-        return {};
-    }
-};
-}
-
-/////////////////////////////////////////////////////////////////////
-// for #1805
-/////////////////////////////////////////////////////////////////////
-
-struct NotSerializableData
-{
-    int mydata;
-    float myfloat;
-};
-
-
-TEST_CASE("regression tests")
+TEST_CASE("regression tests 1")
 {
     SECTION("issue #60 - Double quotation mark is not parsed correctly")
     {
@@ -1651,331 +1577,6 @@ TEST_CASE("regression tests")
         CHECK(ff.x == 3);
         nlohmann::json nj = lj;                // This line works as expected
     }
-
-    SECTION("issue #1001 - Fix memory leak during parser callback")
-    {
-        auto geojsonExample = R"(
-          { "type": "FeatureCollection",
-            "features": [
-              { "type": "Feature",
-                "geometry": {"type": "Point", "coordinates": [102.0, 0.5]},
-                "properties": {"prop0": "value0"}
-                },
-              { "type": "Feature",
-                "geometry": {
-                  "type": "LineString",
-                  "coordinates": [
-                    [102.0, 0.0], [103.0, 1.0], [104.0, 0.0], [105.0, 1.0]
-                    ]
-                  },
-                "properties": {
-                  "prop0": "value0",
-                  "prop1": 0.0
-                  }
-                },
-              { "type": "Feature",
-                 "geometry": {
-                   "type": "Polygon",
-                   "coordinates": [
-                     [ [100.0, 0.0], [101.0, 0.0], [101.0, 1.0],
-                       [100.0, 1.0], [100.0, 0.0] ]
-                     ]
-                 },
-                 "properties": {
-                   "prop0": "value0",
-                   "prop1": {"this": "that"}
-                   }
-                 }
-               ]
-             })";
-
-        json::parser_callback_t cb = [&](int, json::parse_event_t event, json & parsed)
-        {
-            // skip uninteresting events
-            if (event == json::parse_event_t::value && !parsed.is_primitive())
-            {
-                return false;
-            }
-
-            switch (event)
-            {
-                case json::parse_event_t::key:
-                    {
-                        return true;
-                    }
-                case json::parse_event_t::value:
-                    {
-                        return false;
-                    }
-                case json::parse_event_t::object_start:
-                    {
-                        return true;
-                    }
-                case json::parse_event_t::object_end:
-                    {
-                        return false;
-                    }
-                case json::parse_event_t::array_start:
-                    {
-                        return true;
-                    }
-                case json::parse_event_t::array_end:
-                    {
-                        return false;
-                    }
-
-                default:
-                    {
-                        return true;
-                    }
-            }
-        };
-
-        auto j = json::parse(geojsonExample, cb, true);
-        CHECK(j == json());
-    }
-
-    SECTION("issue #1021 - to/from_msgpack only works with standard typization")
-    {
-        float_json j = 1000.0;
-        CHECK(float_json::from_cbor(float_json::to_cbor(j)) == j);
-        CHECK(float_json::from_msgpack(float_json::to_msgpack(j)) == j);
-        CHECK(float_json::from_ubjson(float_json::to_ubjson(j)) == j);
-
-        float_json j2 = {1000.0, 2000.0, 3000.0};
-        CHECK(float_json::from_ubjson(float_json::to_ubjson(j2, true, true)) == j2);
-    }
-
-    SECTION("issue #1045 - Using STL algorithms with JSON containers with expected results?")
-    {
-        json diffs = nlohmann::json::array();
-        json m1{{"key1", 42}};
-        json m2{{"key2", 42}};
-        auto p1 = m1.items();
-        auto p2 = m2.items();
-
-        using it_type = decltype(p1.begin());
-
-        std::set_difference(
-            p1.begin(), p1.end(),
-            p2.begin(), p2.end(),
-            std::inserter(diffs, diffs.end()), [&](const it_type & e1, const it_type & e2) -> bool
-        {
-            using comper_pair = std::pair<std::string, decltype(e1.value())>; // Trying to avoid unneeded copy
-            return comper_pair(e1.key(), e1.value()) < comper_pair(e2.key(), e2.value()); // Using pair comper
-        });
-
-        CHECK(diffs.size() == 1); // Note the change here, was 2
-    }
-
-#ifdef JSON_HAS_CPP_17
-    SECTION("issue #1292 - Serializing std::variant causes stack overflow")
-    {
-        static_assert(
-            !std::is_constructible<json, std::variant<int, float>>::value, "");
-    }
-#endif
-
-    SECTION("issue #1299 - compile error in from_json converting to container "
-            "with std::pair")
-    {
-        json j =
-        {
-            {"1", {{"a", "testa_1"}, {"b", "testb_1"}}},
-            {"2", {{"a", "testa_2"}, {"b", "testb_2"}}},
-            {"3", {{"a", "testa_3"}, {"b", "testb_3"}}},
-        };
-
-        std::map<std::string, Data> expected
-        {
-            {"1", {"testa_1", "testb_1"}},
-            {"2", {"testa_2", "testb_2"}},
-            {"3", {"testa_3", "testb_3"}},
-        };
-        const auto data = j.get<decltype(expected)>();
-        CHECK(expected == data);
-    }
-
-    SECTION("issue #1445 - buffer overflow in dumping invalid utf-8 strings")
-    {
-        SECTION("a bunch of -1, ensure_ascii=true")
-        {
-            const auto length = 300;
-
-            json dump_test;
-            dump_test["1"] = std::string(length, -1);
-
-            std::string expected = "{\"1\":\"";
-            for (int i = 0; i < length; ++i)
-            {
-                expected += "\\ufffd";
-            }
-            expected += "\"}";
-
-            auto s = dump_test.dump(-1, ' ', true, nlohmann::json::error_handler_t::replace);
-            CHECK(s == expected);
-        }
-        SECTION("a bunch of -2, ensure_ascii=false")
-        {
-            const auto length = 500;
-
-            json dump_test;
-            dump_test["1"] = std::string(length, -2);
-
-            std::string expected = "{\"1\":\"";
-            for (int i = 0; i < length; ++i)
-            {
-                expected += "\xEF\xBF\xBD";
-            }
-            expected += "\"}";
-
-            auto s = dump_test.dump(-1, ' ', false, nlohmann::json::error_handler_t::replace);
-            CHECK(s == expected);
-        }
-        SECTION("test case in issue #1445")
-        {
-            nlohmann::json dump_test;
-            const int data[] =
-            {
-                109,  108,  103,  125,  -122, -53,  115,
-                18,   3,    0,    102,  19,   1,    15,
-                -110, 13,   -3,   -1,   -81,  32,   2,
-                0,    0,    0,    0,    0,    0,    0,
-                8,    0,    0,    0,    0,    0,    0,
-                0,    0,    0,    0,    0,    -80,  2,
-                0,    0,    96,   -118, 46,   -116, 46,
-                109,  -84,  -87,  108,  14,   109,  -24,
-                -83,  13,   -18,  -51,  -83,  -52,  -115,
-                14,   6,    32,   0,    0,    0,    0,
-                0,    0,    0,    0,    0,    0,    0,
-                64,   3,    0,    0,    0,    35,   -74,
-                -73,  55,   57,   -128, 0,    0,    0,
-                0,    0,    0,    0,    0,    0,    0,
-                0,    0,    33,   0,    0,    0,    -96,
-                -54,  -28,  -26
-            };
-            std::string s;
-            for (unsigned i = 0; i < sizeof(data) / sizeof(int); i++)
-            {
-                s += static_cast<char>(data[i]);
-            }
-            dump_test["1"] = s;
-            dump_test.dump(-1, ' ', true, nlohmann::json::error_handler_t::replace);
-        }
-    }
-
-    SECTION("issue #1447 - Integer Overflow (OSS-Fuzz 12506)")
-    {
-        json j = json::parse("[-9223372036854775808]");
-        CHECK(j.dump() == "[-9223372036854775808]");
-    }
-
-    SECTION("issue #1708 - minimum value of int64_t can be outputted")
-    {
-        constexpr auto smallest = (std::numeric_limits<int64_t>::min)();
-        json j = smallest;
-        CHECK(j.dump() == std::to_string(smallest));
-    }
-
-    SECTION("issue #1727 - Contains with non-const lvalue json_pointer picks the wrong overload")
-    {
-        json j = {{"root", {{"settings", {{"logging", true}}}}}};
-
-        auto jptr1 = "/root/settings/logging"_json_pointer;
-        auto jptr2 = json::json_pointer{"/root/settings/logging"};
-
-        CHECK(j.contains(jptr1));
-        CHECK(j.contains(jptr2));
-    }
-
-    SECTION("issue #1647 - compile error when deserializing enum if both non-default from_json and non-member operator== exists for other type")
-    {
-        {
-            json j;
-            NonDefaultFromJsonStruct x(j);
-            NonDefaultFromJsonStruct y;
-            CHECK(x == y);
-        }
-
-        auto val = nlohmann::json("one").get<for_1647>();
-        CHECK(val == for_1647::one);
-        json j = val;
-    }
-
-    SECTION("issue #1715 - json::from_cbor does not respect allow_exceptions = false when input is string literal")
-    {
-        SECTION("string literal")
-        {
-            json cbor = json::from_cbor("B", true, false);
-            CHECK(cbor.is_discarded());
-        }
-
-        SECTION("string array")
-        {
-            const char input[] = { 'B', 0x00 };
-            json cbor = json::from_cbor(input, true, false);
-            CHECK(cbor.is_discarded());
-        }
-
-        SECTION("std::string")
-        {
-            json cbor = json::from_cbor(std::string("B"), true, false);
-            CHECK(cbor.is_discarded());
-        }
-    }
-
-    SECTION("issue #1805 - A pair<T1, T2> is json constructible only if T1 and T2 are json constructible")
-    {
-        static_assert(!std::is_constructible<json, std::pair<std::string, NotSerializableData>>::value, "");
-        static_assert(!std::is_constructible<json, std::pair<NotSerializableData, std::string>>::value, "");
-        static_assert(std::is_constructible<json, std::pair<int, std::string>>::value, "");
-    }
-    SECTION("issue #1825 - A tuple<Args..> is json constructible only if all T in Args are json constructible")
-    {
-        static_assert(!std::is_constructible<json, std::tuple<std::string, NotSerializableData>>::value, "");
-        static_assert(!std::is_constructible<json, std::tuple<NotSerializableData, std::string>>::value, "");
-        static_assert(std::is_constructible<json, std::tuple<int, std::string>>::value, "");
-    }
-
-    SECTION("issue #1983 - JSON patch diff for op=add formation is not as per standard (RFC 6902)")
-    {
-        const auto source = R"({ "foo": [ "1", "2" ] })"_json;
-        const auto target = R"({"foo": [ "1", "2", "3" ]})"_json;
-        const auto result = json::diff(source, target);
-        CHECK(result.dump() == R"([{"op":"add","path":"/foo/-","value":"3"}])");
-    }
-
-    SECTION("issue #2067 - cannot serialize binary data to text JSON")
-    {
-        const unsigned char data[] = {0x81, 0xA4, 0x64, 0x61, 0x74, 0x61, 0xC4, 0x0F, 0x33, 0x30, 0x30, 0x32, 0x33, 0x34, 0x30, 0x31, 0x30, 0x37, 0x30, 0x35, 0x30, 0x31, 0x30};
-        json j = json::from_msgpack(data, sizeof(data) / sizeof(data[0]));
-        CHECK_NOTHROW(
-            j.dump(4,                              // Indent
-                   ' ',                            // Indent char
-                   false,                          // Ensure ascii
-                   json::error_handler_t::strict  // Error
-                  )
-        );
-    }
-
-    SECTION("PR #2181 - regression bug with lvalue")
-    {
-        // see https://github.com/nlohmann/json/pull/2181#issuecomment-653326060
-        json j{{"x", "test"}};
-        std::string defval = "default value";
-        auto val = j.value("x", defval);
-        auto val2 = j.value("y", defval);
-    }
-
-    SECTION("issue #2293 - eof doesnt cause parsing to stop")
-    {
-        std::vector<uint8_t> data =
-        {
-            0x7B, 0x6F, 0x62, 0x6A, 0x65, 0x63, 0x74, 0x20, 0x4F, 0x42
-        };
-        json result = json::from_cbor(data, true, false);
-        CHECK(result.is_discarded());
-    }
 }
 
 #if !defined(JSON_NOEXCEPTION)
diff --git a/test/src/unit-regression2.cpp b/test/src/unit-regression2.cpp
new file mode 100644
index 00000000..69e3dea9
--- /dev/null
+++ b/test/src/unit-regression2.cpp
@@ -0,0 +1,488 @@
+/*
+    __ _____ _____ _____
+ __|  |   __|     |   | |  JSON for Modern C++ (test suite)
+|  |  |__   |  |  | | | |  version 3.9.1
+|_____|_____|_____|_|___|  https://github.com/nlohmann/json
+
+Licensed under the MIT License <http://opensource.org/licenses/MIT>.
+SPDX-License-Identifier: MIT
+Copyright (c) 2013-2019 Niels Lohmann <http://nlohmann.me>.
+
+Permission is hereby  granted, free of charge, to any  person obtaining a copy
+of this software and associated  documentation files (the "Software"), to deal
+in the Software  without restriction, including without  limitation the rights
+to  use, copy,  modify, merge,  publish, distribute,  sublicense, and/or  sell
+copies  of  the Software,  and  to  permit persons  to  whom  the Software  is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE  IS PROVIDED "AS  IS", WITHOUT WARRANTY  OF ANY KIND,  EXPRESS OR
+IMPLIED,  INCLUDING BUT  NOT  LIMITED TO  THE  WARRANTIES OF  MERCHANTABILITY,
+FITNESS FOR  A PARTICULAR PURPOSE AND  NONINFRINGEMENT. IN NO EVENT  SHALL THE
+AUTHORS  OR COPYRIGHT  HOLDERS  BE  LIABLE FOR  ANY  CLAIM,  DAMAGES OR  OTHER
+LIABILITY, WHETHER IN AN ACTION OF  CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE  OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+*/
+
+#include "doctest_compatibility.h"
+DOCTEST_GCC_SUPPRESS_WARNING("-Wfloat-equal")
+
+// for some reason including this after the json header leads to linker errors with VS 2017...
+#include <locale>
+
+#define private public
+#include <nlohmann/json.hpp>
+using nlohmann::json;
+#undef private
+
+#include <fstream>
+#include <sstream>
+#include <list>
+#include <cstdio>
+#include <test_data.hpp>
+
+#if (defined(__cplusplus) && __cplusplus >= 201703L) || (defined(_HAS_CXX17) && _HAS_CXX17 == 1) // fix for issue #464
+    #define JSON_HAS_CPP_17
+#endif
+
+#ifdef JSON_HAS_CPP_17
+    #include <variant>
+#endif
+
+/////////////////////////////////////////////////////////////////////
+// for #1021
+/////////////////////////////////////////////////////////////////////
+
+using float_json = nlohmann::basic_json<std::map, std::vector, std::string, bool, std::int64_t, std::uint64_t, float>;
+
+/////////////////////////////////////////////////////////////////////
+// for #1647
+/////////////////////////////////////////////////////////////////////
+namespace
+{
+struct NonDefaultFromJsonStruct { };
+
+inline bool operator== (NonDefaultFromJsonStruct const&, NonDefaultFromJsonStruct const&)
+{
+    return true;
+}
+
+enum class for_1647 { one, two };
+
+NLOHMANN_JSON_SERIALIZE_ENUM(for_1647,
+{
+    {for_1647::one, "one"},
+    {for_1647::two, "two"},
+})
+}
+
+/////////////////////////////////////////////////////////////////////
+// for #1299
+/////////////////////////////////////////////////////////////////////
+
+struct Data
+{
+    Data() = default;
+    Data(const std::string& a_, const std::string b_) : a(a_), b(b_) {}
+    std::string a {};
+    std::string b {};
+};
+
+void from_json(const json& j, Data& data)
+{
+    j["a"].get_to(data.a);
+    j["b"].get_to(data.b);
+}
+
+bool operator==(Data const& lhs, Data const& rhs)
+{
+    return lhs.a == rhs.a && lhs.b == rhs.b;
+}
+
+//bool operator!=(Data const& lhs, Data const& rhs)
+//{
+//    return !(lhs == rhs);
+//}
+
+namespace nlohmann
+{
+template <>
+struct adl_serializer<NonDefaultFromJsonStruct>
+{
+    static NonDefaultFromJsonStruct from_json (json const&) noexcept
+    {
+        return {};
+    }
+};
+}
+
+/////////////////////////////////////////////////////////////////////
+// for #1805
+/////////////////////////////////////////////////////////////////////
+
+struct NotSerializableData
+{
+    int mydata;
+    float myfloat;
+};
+
+
+TEST_CASE("regression tests 2")
+{
+    SECTION("issue #1001 - Fix memory leak during parser callback")
+    {
+        auto geojsonExample = R"(
+          { "type": "FeatureCollection",
+            "features": [
+              { "type": "Feature",
+                "geometry": {"type": "Point", "coordinates": [102.0, 0.5]},
+                "properties": {"prop0": "value0"}
+                },
+              { "type": "Feature",
+                "geometry": {
+                  "type": "LineString",
+                  "coordinates": [
+                    [102.0, 0.0], [103.0, 1.0], [104.0, 0.0], [105.0, 1.0]
+                    ]
+                  },
+                "properties": {
+                  "prop0": "value0",
+                  "prop1": 0.0
+                  }
+                },
+              { "type": "Feature",
+                 "geometry": {
+                   "type": "Polygon",
+                   "coordinates": [
+                     [ [100.0, 0.0], [101.0, 0.0], [101.0, 1.0],
+                       [100.0, 1.0], [100.0, 0.0] ]
+                     ]
+                 },
+                 "properties": {
+                   "prop0": "value0",
+                   "prop1": {"this": "that"}
+                   }
+                 }
+               ]
+             })";
+
+        json::parser_callback_t cb = [&](int, json::parse_event_t event, json & parsed)
+        {
+            // skip uninteresting events
+            if (event == json::parse_event_t::value && !parsed.is_primitive())
+            {
+                return false;
+            }
+
+            switch (event)
+            {
+                case json::parse_event_t::key:
+                {
+                    return true;
+                }
+                case json::parse_event_t::value:
+                {
+                    return false;
+                }
+                case json::parse_event_t::object_start:
+                {
+                    return true;
+                }
+                case json::parse_event_t::object_end:
+                {
+                    return false;
+                }
+                case json::parse_event_t::array_start:
+                {
+                    return true;
+                }
+                case json::parse_event_t::array_end:
+                {
+                    return false;
+                }
+
+                default:
+                {
+                    return true;
+                }
+            }
+        };
+
+        auto j = json::parse(geojsonExample, cb, true);
+        CHECK(j == json());
+    }
+
+    SECTION("issue #1021 - to/from_msgpack only works with standard typization")
+    {
+        float_json j = 1000.0;
+        CHECK(float_json::from_cbor(float_json::to_cbor(j)) == j);
+        CHECK(float_json::from_msgpack(float_json::to_msgpack(j)) == j);
+        CHECK(float_json::from_ubjson(float_json::to_ubjson(j)) == j);
+
+        float_json j2 = {1000.0, 2000.0, 3000.0};
+        CHECK(float_json::from_ubjson(float_json::to_ubjson(j2, true, true)) == j2);
+    }
+
+    SECTION("issue #1045 - Using STL algorithms with JSON containers with expected results?")
+    {
+        json diffs = nlohmann::json::array();
+        json m1{{"key1", 42}};
+        json m2{{"key2", 42}};
+        auto p1 = m1.items();
+        auto p2 = m2.items();
+
+        using it_type = decltype(p1.begin());
+
+        std::set_difference(
+            p1.begin(), p1.end(),
+            p2.begin(), p2.end(),
+            std::inserter(diffs, diffs.end()), [&](const it_type & e1, const it_type & e2) -> bool
+        {
+            using comper_pair = std::pair<std::string, decltype(e1.value())>; // Trying to avoid unneeded copy
+            return comper_pair(e1.key(), e1.value()) < comper_pair(e2.key(), e2.value()); // Using pair comper
+        });
+
+        CHECK(diffs.size() == 1); // Note the change here, was 2
+    }
+
+#ifdef JSON_HAS_CPP_17
+    SECTION("issue #1292 - Serializing std::variant causes stack overflow")
+    {
+        static_assert(
+            !std::is_constructible<json, std::variant<int, float>>::value, "");
+    }
+#endif
+
+    SECTION("issue #1299 - compile error in from_json converting to container "
+            "with std::pair")
+    {
+        json j =
+        {
+            {"1", {{"a", "testa_1"}, {"b", "testb_1"}}},
+            {"2", {{"a", "testa_2"}, {"b", "testb_2"}}},
+            {"3", {{"a", "testa_3"}, {"b", "testb_3"}}},
+        };
+
+        std::map<std::string, Data> expected
+        {
+            {"1", {"testa_1", "testb_1"}},
+            {"2", {"testa_2", "testb_2"}},
+            {"3", {"testa_3", "testb_3"}},
+        };
+        const auto data = j.get<decltype(expected)>();
+        CHECK(expected == data);
+    }
+
+    SECTION("issue #1445 - buffer overflow in dumping invalid utf-8 strings")
+    {
+        SECTION("a bunch of -1, ensure_ascii=true")
+        {
+            const auto length = 300;
+
+            json dump_test;
+            dump_test["1"] = std::string(length, -1);
+
+            std::string expected = "{\"1\":\"";
+            for (int i = 0; i < length; ++i)
+            {
+                expected += "\\ufffd";
+            }
+            expected += "\"}";
+
+            auto s = dump_test.dump(-1, ' ', true, nlohmann::json::error_handler_t::replace);
+            CHECK(s == expected);
+        }
+        SECTION("a bunch of -2, ensure_ascii=false")
+        {
+            const auto length = 500;
+
+            json dump_test;
+            dump_test["1"] = std::string(length, -2);
+
+            std::string expected = "{\"1\":\"";
+            for (int i = 0; i < length; ++i)
+            {
+                expected += "\xEF\xBF\xBD";
+            }
+            expected += "\"}";
+
+            auto s = dump_test.dump(-1, ' ', false, nlohmann::json::error_handler_t::replace);
+            CHECK(s == expected);
+        }
+        SECTION("test case in issue #1445")
+        {
+            nlohmann::json dump_test;
+            const int data[] =
+            {
+                109,  108,  103,  125,  -122, -53,  115,
+                18,   3,    0,    102,  19,   1,    15,
+                -110, 13,   -3,   -1,   -81,  32,   2,
+                0,    0,    0,    0,    0,    0,    0,
+                8,    0,    0,    0,    0,    0,    0,
+                0,    0,    0,    0,    0,    -80,  2,
+                0,    0,    96,   -118, 46,   -116, 46,
+                109,  -84,  -87,  108,  14,   109,  -24,
+                -83,  13,   -18,  -51,  -83,  -52,  -115,
+                14,   6,    32,   0,    0,    0,    0,
+                0,    0,    0,    0,    0,    0,    0,
+                64,   3,    0,    0,    0,    35,   -74,
+                -73,  55,   57,   -128, 0,    0,    0,
+                0,    0,    0,    0,    0,    0,    0,
+                0,    0,    33,   0,    0,    0,    -96,
+                -54,  -28,  -26
+            };
+            std::string s;
+            for (unsigned i = 0; i < sizeof(data) / sizeof(int); i++)
+            {
+                s += static_cast<char>(data[i]);
+            }
+            dump_test["1"] = s;
+            dump_test.dump(-1, ' ', true, nlohmann::json::error_handler_t::replace);
+        }
+    }
+
+    SECTION("issue #1447 - Integer Overflow (OSS-Fuzz 12506)")
+    {
+        json j = json::parse("[-9223372036854775808]");
+        CHECK(j.dump() == "[-9223372036854775808]");
+    }
+
+    SECTION("issue #1708 - minimum value of int64_t can be outputted")
+    {
+        constexpr auto smallest = (std::numeric_limits<int64_t>::min)();
+        json j = smallest;
+        CHECK(j.dump() == std::to_string(smallest));
+    }
+
+    SECTION("issue #1727 - Contains with non-const lvalue json_pointer picks the wrong overload")
+    {
+        json j = {{"root", {{"settings", {{"logging", true}}}}}};
+
+        auto jptr1 = "/root/settings/logging"_json_pointer;
+        auto jptr2 = json::json_pointer{"/root/settings/logging"};
+
+        CHECK(j.contains(jptr1));
+        CHECK(j.contains(jptr2));
+    }
+
+    SECTION("issue #1647 - compile error when deserializing enum if both non-default from_json and non-member operator== exists for other type")
+    {
+        {
+            json j;
+            NonDefaultFromJsonStruct x(j);
+            NonDefaultFromJsonStruct y;
+            CHECK(x == y);
+        }
+
+        auto val = nlohmann::json("one").get<for_1647>();
+        CHECK(val == for_1647::one);
+        json j = val;
+    }
+
+    SECTION("issue #1715 - json::from_cbor does not respect allow_exceptions = false when input is string literal")
+    {
+        SECTION("string literal")
+        {
+            json cbor = json::from_cbor("B", true, false);
+            CHECK(cbor.is_discarded());
+        }
+
+        SECTION("string array")
+        {
+            const char input[] = { 'B', 0x00 };
+            json cbor = json::from_cbor(input, true, false);
+            CHECK(cbor.is_discarded());
+        }
+
+        SECTION("std::string")
+        {
+            json cbor = json::from_cbor(std::string("B"), true, false);
+            CHECK(cbor.is_discarded());
+        }
+    }
+
+    SECTION("issue #1805 - A pair<T1, T2> is json constructible only if T1 and T2 are json constructible")
+    {
+        static_assert(!std::is_constructible<json, std::pair<std::string, NotSerializableData>>::value, "");
+        static_assert(!std::is_constructible<json, std::pair<NotSerializableData, std::string>>::value, "");
+        static_assert(std::is_constructible<json, std::pair<int, std::string>>::value, "");
+    }
+    SECTION("issue #1825 - A tuple<Args..> is json constructible only if all T in Args are json constructible")
+    {
+        static_assert(!std::is_constructible<json, std::tuple<std::string, NotSerializableData>>::value, "");
+        static_assert(!std::is_constructible<json, std::tuple<NotSerializableData, std::string>>::value, "");
+        static_assert(std::is_constructible<json, std::tuple<int, std::string>>::value, "");
+    }
+
+    SECTION("issue #1983 - JSON patch diff for op=add formation is not as per standard (RFC 6902)")
+    {
+        const auto source = R"({ "foo": [ "1", "2" ] })"_json;
+        const auto target = R"({"foo": [ "1", "2", "3" ]})"_json;
+        const auto result = json::diff(source, target);
+        CHECK(result.dump() == R"([{"op":"add","path":"/foo/-","value":"3"}])");
+    }
+
+    SECTION("issue #2067 - cannot serialize binary data to text JSON")
+    {
+        const unsigned char data[] = {0x81, 0xA4, 0x64, 0x61, 0x74, 0x61, 0xC4, 0x0F, 0x33, 0x30, 0x30, 0x32, 0x33, 0x34, 0x30, 0x31, 0x30, 0x37, 0x30, 0x35, 0x30, 0x31, 0x30};
+        json j = json::from_msgpack(data, sizeof(data) / sizeof(data[0]));
+        CHECK_NOTHROW(
+            j.dump(4,                              // Indent
+                   ' ',                            // Indent char
+                   false,                          // Ensure ascii
+                   json::error_handler_t::strict  // Error
+                  )
+        );
+    }
+
+    SECTION("PR #2181 - regression bug with lvalue")
+    {
+        // see https://github.com/nlohmann/json/pull/2181#issuecomment-653326060
+        json j{{"x", "test"}};
+        std::string defval = "default value";
+        auto val = j.value("x", defval);
+        auto val2 = j.value("y", defval);
+    }
+
+    SECTION("issue #2293 - eof doesnt cause parsing to stop")
+    {
+        std::vector<uint8_t> data =
+        {
+            0x7B, 0x6F, 0x62, 0x6A, 0x65, 0x63, 0x74, 0x20, 0x4F, 0x42
+        };
+        json result = json::from_cbor(data, true, false);
+        CHECK(result.is_discarded());
+    }
+
+    SECTION("issue #2315 - json.update and vector<pair>does not work with ordered_json")
+    {
+        nlohmann::ordered_json jsonAnimals = {{"animal", "dog"}};
+        nlohmann::ordered_json jsonCat = {{"animal", "cat"}};
+        jsonAnimals.update(jsonCat);
+        CHECK(jsonAnimals["animal"] == "cat");
+
+        auto jsonAnimals_parsed = nlohmann::ordered_json::parse(jsonAnimals.dump());
+        CHECK(jsonAnimals == jsonAnimals_parsed);
+
+        std::vector<std::pair<std::string, int64_t>> intData = {std::make_pair("aaaa", 11),
+                                                                std::make_pair("bbb", 222)
+                                                               };
+        nlohmann::ordered_json jsonObj;
+        for (const auto& data : intData)
+        {
+            jsonObj[data.first] = data.second;
+        }
+        CHECK(jsonObj["aaaa"] == 11);
+        CHECK(jsonObj["bbb"] == 222);
+    }
+
+    SECTION("issue #2330 - ignore_comment=true fails on multiple consecutive lines starting with comments")
+    {
+        std::string ss = "//\n//\n{\n}\n";
+        json j = json::parse(ss, nullptr, true, true);
+        CHECK(j.dump() == "{}");
+    }
+}
diff --git a/test/src/unit-serialization.cpp b/test/src/unit-serialization.cpp
index 2308dd2a..3a733d2f 100644
--- a/test/src/unit-serialization.cpp
+++ b/test/src/unit-serialization.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-testsuites.cpp b/test/src/unit-testsuites.cpp
index f5e0ec10..da8b27d7 100644
--- a/test/src/unit-testsuites.cpp
+++ b/test/src/unit-testsuites.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-to_chars.cpp b/test/src/unit-to_chars.cpp
index 386c4cc2..2861928f 100644
--- a/test/src/unit-to_chars.cpp
+++ b/test/src/unit-to_chars.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-ubjson.cpp b/test/src/unit-ubjson.cpp
index 3c72ddbb..42954479 100644
--- a/test/src/unit-ubjson.cpp
+++ b/test/src/unit-ubjson.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-udt.cpp b/test/src/unit-udt.cpp
index 2374b3e3..7f74ac5f 100644
--- a/test/src/unit-udt.cpp
+++ b/test/src/unit-udt.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-udt_macro.cpp b/test/src/unit-udt_macro.cpp
index 45eeca2e..b56a5d15 100644
--- a/test/src/unit-udt_macro.cpp
+++ b/test/src/unit-udt_macro.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-unicode.cpp b/test/src/unit-unicode.cpp
index 0b60b359..8e122d5d 100644
--- a/test/src/unit-unicode.cpp
+++ b/test/src/unit-unicode.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-user_defined_input.cpp b/test/src/unit-user_defined_input.cpp
index 967f9c06..5a1138b0 100644
--- a/test/src/unit-user_defined_input.cpp
+++ b/test/src/unit-user_defined_input.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit-wstring.cpp b/test/src/unit-wstring.cpp
index 2ebe99fb..a5b80be7 100644
--- a/test/src/unit-wstring.cpp
+++ b/test/src/unit-wstring.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/test/src/unit.cpp b/test/src/unit.cpp
index b0b20d79..f54819e1 100644
--- a/test/src/unit.cpp
+++ b/test/src/unit.cpp
@@ -1,7 +1,7 @@
 /*
     __ _____ _____ _____
  __|  |   __|     |   | |  JSON for Modern C++ (test suite)
-|  |  |__   |  |  | | | |  version 3.9.0
+|  |  |__   |  |  | | | |  version 3.9.1
 |_____|_____|_____|_|___|  https://github.com/nlohmann/json
 
 Licensed under the MIT License <http://opensource.org/licenses/MIT>.
diff --git a/wsjcpp.yml b/wsjcpp.yml
index 629ae388..d8184952 100644
--- a/wsjcpp.yml
+++ b/wsjcpp.yml
@@ -2,7 +2,7 @@ wsjcpp_version: "v0.1.1"
 cmake_minimum_required: "3.0"
 cmake_cxx_standard: "11"
 name: "nlohmann/json"
-version: "v3.9.0"
+version: "v3.9.1"
 description: "JSON for Modern C++"
 issues: "https://github.com/nlohmann/json/issues"
 keywords: