diff --git a/src/json.hpp b/src/json.hpp
index 2dd55104..9af2a98d 100644
--- a/src/json.hpp
+++ b/src/json.hpp
@@ -8862,7 +8862,8 @@ class basic_json
             // We initially read a lot of characters into the buffer, and we
             // may not have processed all of them. Therefore, we need to
             // "rewind" the stream after the last processed char.
-            is.seekg(start_position + static_cast<std::streamoff>(processed_chars));
+            is.seekg(start_position);
+            is.ignore(processed_chars);
             // clear stream flags
             is.clear();
         }
diff --git a/test/src/unit-regression.cpp b/test/src/unit-regression.cpp
index ec8ba6ad..f4f1f61d 100644
--- a/test/src/unit-regression.cpp
+++ b/test/src/unit-regression.cpp
@@ -711,7 +711,6 @@ TEST_CASE("regression tests")
                               "[json.exception.parse_error.101] parse error at 1: syntax error - unexpected end of input");
         }
 
-        /*
         SECTION("second example from #529")
         {
             std::string str = "{\n\"one\"   : 1,\n\"two\"   : 2\n}\n{\n\"three\" : 3\n}";
@@ -749,7 +748,6 @@ TEST_CASE("regression tests")
 
             std::remove("test.json");
         }
-        */
     }
 
     SECTION("issue #389 - Integer-overflow (OSS-Fuzz issue 267)")