diff --git a/src/json.hpp b/src/json.hpp
index 1016ab18..3c338eb8 100644
--- a/src/json.hpp
+++ b/src/json.hpp
@@ -44,7 +44,7 @@ SOFTWARE.
 #include <initializer_list> // initializer_list
 #include <iomanip> // hex
 #include <iosfwd>   // istream, ostream
-#include <iterator> // advance, begin, back_inserter, distance, end, inserter, iterator, iterator_traits, next, random_access_iterator_tag, reverse_iterator
+#include <iterator> // advance, begin, back_inserter, bidirectional_iterator_tag, distance, end, inserter, iterator, iterator_traits, next, random_access_iterator_tag, reverse_iterator
 #include <limits> // numeric_limits
 #include <locale> // locale
 #include <map> // map
@@ -281,6 +281,8 @@ json.exception.invalid_iterator.204 | iterators out of range | When an iterator
 json.exception.invalid_iterator.205 | iterator out of range | When an iterator for a primitive type (number, boolean, or string) is passed to an erase function, the iterator has to be the @ref begin() iterator, because it is the only way to address the stored value. All other iterators are invalid.
 json.exception.invalid_iterator.206 | cannot construct with iterators from null | The iterators passed to constructor @ref basic_json(InputIT first, InputIT last) belong to a JSON null value and hence to not define a valid range.
 json.exception.invalid_iterator.207 | cannot use key() for non-object iterators | The key() member function can only be used on iterators belonging to a JSON object, because other types do not have a concept of a key.
+json.exception.invalid_iterator.208 | cannot use operator[] for object iterators | The operator[] to specify a concrete offset cannot be used on iterators belonging to a JSON object, because JSON objects are unordered.
+json.exception.invalid_iterator.209 | cannot use offsets with object iterators | The offset operators (+, -, +=, -=) cannot be used on iterators belonging to a JSON object, because JSON objects are unordered.
 json.exception.invalid_iterator.210 | iterators do not fit | The iterator range passed to the insert function are not compatible, meaning they do not belong to the same container. Therefore, the range (@a first, @a last) is invalid.
 json.exception.invalid_iterator.211 | passed iterators may not belong to container | The iterator range passed to the insert function must not be a subrange of the container to insert to.
 json.exception.invalid_iterator.212 | cannot compare iterators of different containers | When two iterators are compared, they must belong to the same container.
@@ -3553,7 +3555,7 @@ class iter_impl : public std::iterator<std::random_access_iterator_tag, BasicJso
         typename BasicJsonType::const_reference,
         typename BasicJsonType::reference>::type;
     /// the category of the iterator
-    using iterator_category = std::random_access_iterator_tag;
+    using iterator_category = std::bidirectional_iterator_tag;
 
     /// default constructor
     iter_impl() = default;
@@ -3947,8 +3949,7 @@ class iter_impl : public std::iterator<std::random_access_iterator_tag, BasicJso
         switch (m_object->m_type)
         {
             case value_t::object:
-                std::advance(m_it.object_iterator, i);
-                break;
+                JSON_THROW(invalid_iterator::create(209, "cannot use offsets with object iterators"));
 
             case value_t::array:
             {
@@ -4019,11 +4020,7 @@ class iter_impl : public std::iterator<std::random_access_iterator_tag, BasicJso
         switch (m_object->m_type)
         {
             case value_t::object:
-            {
-                difference_type result = 0;
-                for (auto it = other; it != *this; ++it, ++result);
-                return result;
-            }
+                JSON_THROW(invalid_iterator::create(209, "cannot use offsets with object iterators"));
 
             case value_t::array:
                 return m_it.array_iterator - other.m_it.array_iterator;
@@ -4044,11 +4041,7 @@ class iter_impl : public std::iterator<std::random_access_iterator_tag, BasicJso
         switch (m_object->m_type)
         {
             case value_t::object:
-            {
-                auto it = *this;
-                std::advance(it.m_it.object_iterator, n);
-                return *it;
-            }
+                JSON_THROW(invalid_iterator::create(208, "cannot use operator[] for object iterators"));
 
             case value_t::array:
                 return *std::next(m_it.array_iterator, n);
@@ -13194,7 +13187,7 @@ class basic_json
     */
     template<typename A1, typename A2,
              detail::enable_if_t<std::is_constructible<detail::input_adapter, A1, A2>::value, int> = 0>
-    static basic_json from_cbor(A1 && a1, A2 && a2, const bool strict = true)
+    static basic_json from_cbor(A1&& a1, A2&& a2, const bool strict = true)
     {
         return binary_reader(detail::input_adapter(std::forward<A1>(a1), std::forward<A2>(a2))).parse_cbor(strict);
     }
@@ -13281,7 +13274,7 @@ class basic_json
     */
     template<typename A1, typename A2,
              detail::enable_if_t<std::is_constructible<detail::input_adapter, A1, A2>::value, int> = 0>
-    static basic_json from_msgpack(A1 && a1, A2 && a2, const bool strict = true)
+    static basic_json from_msgpack(A1&& a1, A2&& a2, const bool strict = true)
     {
         return binary_reader(detail::input_adapter(std::forward<A1>(a1), std::forward<A2>(a2))).parse_msgpack(strict);
     }
diff --git a/test/src/unit-algorithms.cpp b/test/src/unit-algorithms.cpp
index e67ea404..5a106b6a 100644
--- a/test/src/unit-algorithms.cpp
+++ b/test/src/unit-algorithms.cpp
@@ -240,8 +240,9 @@ TEST_CASE("algorithms")
             SECTION("sorting an object")
             {
                 json j({{"one", 1}, {"two", 2}});
-                std::sort(j.begin(), j.end());
-                CHECK(j == json({{"one", 1}, {"two", 2}}));
+                CHECK_THROWS_AS(std::sort(j.begin(), j.end()), json::invalid_iterator&);
+                CHECK_THROWS_WITH(std::sort(j.begin(), j.end()),
+                                  "[json.exception.invalid_iterator.209] cannot use offsets with object iterators");
             }
         }
 
diff --git a/test/src/unit-iterators2.cpp b/test/src/unit-iterators2.cpp
index 6391b54b..be4e2770 100644
--- a/test/src/unit-iterators2.cpp
+++ b/test/src/unit-iterators2.cpp
@@ -240,7 +240,7 @@ TEST_CASE("iterators 2")
 
     SECTION("iterator arithmetic")
     {
-        json j_object = {{"one", 1}, {"two", 2}, {"three", 3}, {"four", 4}};
+        json j_object = {{"one", 1}, {"two", 2}, {"three", 3}};
         json j_array = {1, 2, 3, 4, 5, 6};
         json j_null = nullptr;
         json j_value = 42;
@@ -251,25 +251,63 @@ TEST_CASE("iterators 2")
             {
                 {
                     auto it = j_object.begin();
-                    it += 3;
-                    CHECK((j_object.begin() + 3) == it);
-                    CHECK((3 + j_object.begin()) == it);
-                    CHECK((it - 3) == j_object.begin());
-                    CHECK((it - j_object.begin()) == 3);
-                    CHECK(*it == json(2));
-                    it -= 2;
-                    CHECK(*it == json(1));
+                    CHECK_THROWS_AS(it += 1, json::invalid_iterator&);
+                    CHECK_THROWS_WITH(it += 1, "[json.exception.invalid_iterator.209] cannot use offsets with object iterators");
                 }
                 {
                     auto it = j_object.cbegin();
-                    it += 3;
-                    CHECK((j_object.cbegin() + 3) == it);
-                    CHECK((3 + j_object.cbegin()) == it);
-                    CHECK((it - 3) == j_object.cbegin());
-                    CHECK((it - j_object.cbegin()) == 3);
-                    CHECK(*it == json(2));
-                    it -= 2;
-                    CHECK(*it == json(1));
+                    CHECK_THROWS_AS(it += 1, json::invalid_iterator&);
+                    CHECK_THROWS_WITH(it += 1, "[json.exception.invalid_iterator.209] cannot use offsets with object iterators");
+                }
+                {
+                    auto it = j_object.begin();
+                    CHECK_THROWS_AS(it + 1, json::invalid_iterator&);
+                    CHECK_THROWS_WITH(it + 1, "[json.exception.invalid_iterator.209] cannot use offsets with object iterators");
+                }
+                {
+                    auto it = j_object.cbegin();
+                    CHECK_THROWS_AS(it + 1, json::invalid_iterator&);
+                    CHECK_THROWS_WITH(it + 1, "[json.exception.invalid_iterator.209] cannot use offsets with object iterators");
+                }
+                {
+                    auto it = j_object.begin();
+                    CHECK_THROWS_AS(1 + it, json::invalid_iterator&);
+                    CHECK_THROWS_WITH(1 + it, "[json.exception.invalid_iterator.209] cannot use offsets with object iterators");
+                }
+                {
+                    auto it = j_object.cbegin();
+                    CHECK_THROWS_AS(1 + it, json::invalid_iterator&);
+                    CHECK_THROWS_WITH(1 + it, "[json.exception.invalid_iterator.209] cannot use offsets with object iterators");
+                }
+                {
+                    auto it = j_object.begin();
+                    CHECK_THROWS_AS(it -= 1, json::invalid_iterator&);
+                    CHECK_THROWS_WITH(it -= 1, "[json.exception.invalid_iterator.209] cannot use offsets with object iterators");
+                }
+                {
+                    auto it = j_object.cbegin();
+                    CHECK_THROWS_AS(it -= 1, json::invalid_iterator&);
+                    CHECK_THROWS_WITH(it -= 1, "[json.exception.invalid_iterator.209] cannot use offsets with object iterators");
+                }
+                {
+                    auto it = j_object.begin();
+                    CHECK_THROWS_AS(it - 1, json::invalid_iterator&);
+                    CHECK_THROWS_WITH(it - 1, "[json.exception.invalid_iterator.209] cannot use offsets with object iterators");
+                }
+                {
+                    auto it = j_object.cbegin();
+                    CHECK_THROWS_AS(it - 1, json::invalid_iterator&);
+                    CHECK_THROWS_WITH(it - 1, "[json.exception.invalid_iterator.209] cannot use offsets with object iterators");
+                }
+                {
+                    auto it = j_object.begin();
+                    CHECK_THROWS_AS(it - it, json::invalid_iterator&);
+                    CHECK_THROWS_WITH(it - it, "[json.exception.invalid_iterator.209] cannot use offsets with object iterators");
+                }
+                {
+                    auto it = j_object.cbegin();
+                    CHECK_THROWS_AS(it - it, json::invalid_iterator&);
+                    CHECK_THROWS_WITH(it - it, "[json.exception.invalid_iterator.209] cannot use offsets with object iterators");
                 }
             }
 
@@ -358,17 +396,17 @@ TEST_CASE("iterators 2")
             {
                 {
                     auto it = j_object.begin();
-                    CHECK(it[0] == json(4));
-                    CHECK(it[1] == json(1));
-                    CHECK(it[2] == json(3));
-                    CHECK(it[3] == json(2));
+                    CHECK_THROWS_AS(it[0], json::invalid_iterator&);
+                    CHECK_THROWS_AS(it[1], json::invalid_iterator&);
+                    CHECK_THROWS_WITH(it[0], "[json.exception.invalid_iterator.208] cannot use operator[] for object iterators");
+                    CHECK_THROWS_WITH(it[1], "[json.exception.invalid_iterator.208] cannot use operator[] for object iterators");
                 }
                 {
                     auto it = j_object.cbegin();
-                    CHECK(it[0] == json(4));
-                    CHECK(it[1] == json(1));
-                    CHECK(it[2] == json(3));
-                    CHECK(it[3] == json(2));
+                    CHECK_THROWS_AS(it[0], json::invalid_iterator&);
+                    CHECK_THROWS_AS(it[1], json::invalid_iterator&);
+                    CHECK_THROWS_WITH(it[0], "[json.exception.invalid_iterator.208] cannot use operator[] for object iterators");
+                    CHECK_THROWS_WITH(it[1], "[json.exception.invalid_iterator.208] cannot use operator[] for object iterators");
                 }
             }
 
@@ -637,7 +675,7 @@ TEST_CASE("iterators 2")
 
     SECTION("reverse iterator arithmetic")
     {
-        json j_object = {{"one", 1}, {"two", 2}, {"three", 3}, {"four", 4}};
+        json j_object = {{"one", 1}, {"two", 2}, {"three", 3}};
         json j_array = {1, 2, 3, 4, 5, 6};
         json j_null = nullptr;
         json j_value = 42;
@@ -648,25 +686,63 @@ TEST_CASE("iterators 2")
             {
                 {
                     auto it = j_object.rbegin();
-                    it += 3;
-                    CHECK((j_object.rbegin() + 3) == it);
-                    CHECK(json::reverse_iterator(3 + j_object.rbegin()) == it);
-                    CHECK((it - 3) == j_object.rbegin());
-                    CHECK((it - j_object.rbegin()) == 3);
-                    CHECK(*it == json(4));
-                    it -= 2;
-                    CHECK(*it == json(3));
+                    CHECK_THROWS_AS(it += 1, json::invalid_iterator&);
+                    CHECK_THROWS_WITH(it += 1, "[json.exception.invalid_iterator.209] cannot use offsets with object iterators");
                 }
                 {
                     auto it = j_object.crbegin();
-                    it += 3;
-                    CHECK((j_object.crbegin() + 3) == it);
-                    CHECK(json::const_reverse_iterator(3 + j_object.crbegin()) == it);
-                    CHECK((it - 3) == j_object.crbegin());
-                    CHECK((it - j_object.crbegin()) == 3);
-                    CHECK(*it == json(4));
-                    it -= 2;
-                    CHECK(*it == json(3));
+                    CHECK_THROWS_AS(it += 1, json::invalid_iterator&);
+                    CHECK_THROWS_WITH(it += 1, "[json.exception.invalid_iterator.209] cannot use offsets with object iterators");
+                }
+                {
+                    auto it = j_object.rbegin();
+                    CHECK_THROWS_AS(it + 1, json::invalid_iterator&);
+                    CHECK_THROWS_WITH(it + 1, "[json.exception.invalid_iterator.209] cannot use offsets with object iterators");
+                }
+                {
+                    auto it = j_object.crbegin();
+                    CHECK_THROWS_AS(it + 1, json::invalid_iterator&);
+                    CHECK_THROWS_WITH(it + 1, "[json.exception.invalid_iterator.209] cannot use offsets with object iterators");
+                }
+                {
+                    auto it = j_object.rbegin();
+                    CHECK_THROWS_AS(1 + it, json::invalid_iterator&);
+                    CHECK_THROWS_WITH(1 + it, "[json.exception.invalid_iterator.209] cannot use offsets with object iterators");
+                }
+                {
+                    auto it = j_object.crbegin();
+                    CHECK_THROWS_AS(1 + it, json::invalid_iterator&);
+                    CHECK_THROWS_WITH(1 + it, "[json.exception.invalid_iterator.209] cannot use offsets with object iterators");
+                }
+                {
+                    auto it = j_object.rbegin();
+                    CHECK_THROWS_AS(it -= 1, json::invalid_iterator&);
+                    CHECK_THROWS_WITH(it -= 1, "[json.exception.invalid_iterator.209] cannot use offsets with object iterators");
+                }
+                {
+                    auto it = j_object.crbegin();
+                    CHECK_THROWS_AS(it -= 1, json::invalid_iterator&);
+                    CHECK_THROWS_WITH(it -= 1, "[json.exception.invalid_iterator.209] cannot use offsets with object iterators");
+                }
+                {
+                    auto it = j_object.rbegin();
+                    CHECK_THROWS_AS(it - 1, json::invalid_iterator&);
+                    CHECK_THROWS_WITH(it - 1, "[json.exception.invalid_iterator.209] cannot use offsets with object iterators");
+                }
+                {
+                    auto it = j_object.crbegin();
+                    CHECK_THROWS_AS(it - 1, json::invalid_iterator&);
+                    CHECK_THROWS_WITH(it - 1, "[json.exception.invalid_iterator.209] cannot use offsets with object iterators");
+                }
+                {
+                    auto it = j_object.rbegin();
+                    CHECK_THROWS_AS(it - it, json::invalid_iterator&);
+                    CHECK_THROWS_WITH(it - it, "[json.exception.invalid_iterator.209] cannot use offsets with object iterators");
+                }
+                {
+                    auto it = j_object.crbegin();
+                    CHECK_THROWS_AS(it - it, json::invalid_iterator&);
+                    CHECK_THROWS_WITH(it - it, "[json.exception.invalid_iterator.209] cannot use offsets with object iterators");
                 }
             }
 
@@ -755,17 +831,17 @@ TEST_CASE("iterators 2")
             {
                 {
                     auto it = j_object.rbegin();
-                    CHECK(it[0] == json(2));
-                    CHECK(it[1] == json(3));
-                    CHECK(it[2] == json(1));
-                    CHECK(it[3] == json(4));
+                    CHECK_THROWS_AS(it[0], json::invalid_iterator&);
+                    CHECK_THROWS_AS(it[1], json::invalid_iterator&);
+                    CHECK_THROWS_WITH(it[0], "[json.exception.invalid_iterator.209] cannot use offsets with object iterators");
+                    CHECK_THROWS_WITH(it[1], "[json.exception.invalid_iterator.209] cannot use offsets with object iterators");
                 }
                 {
                     auto it = j_object.crbegin();
-                    CHECK(it[0] == json(2));
-                    CHECK(it[1] == json(3));
-                    CHECK(it[2] == json(1));
-                    CHECK(it[3] == json(4));
+                    CHECK_THROWS_AS(it[0], json::invalid_iterator&);
+                    CHECK_THROWS_AS(it[1], json::invalid_iterator&);
+                    CHECK_THROWS_WITH(it[0], "[json.exception.invalid_iterator.209] cannot use offsets with object iterators");
+                    CHECK_THROWS_WITH(it[1], "[json.exception.invalid_iterator.209] cannot use offsets with object iterators");
                 }
             }