diff --git a/test/src/unit-class_parser.cpp b/test/src/unit-class_parser.cpp
index c356937fd2..08d4d6efe7 100644
--- a/test/src/unit-class_parser.cpp
+++ b/test/src/unit-class_parser.cpp
@@ -205,6 +205,18 @@ TEST_CASE("parser class")
                 CHECK_THROWS_WITH(parser_helper("\"\x1d\""), "[json.exception.parse_error.101] parse error at 2: syntax error - invalid string: control character must be escaped; last read: '\"<U+001D>'");
                 CHECK_THROWS_WITH(parser_helper("\"\x1e\""), "[json.exception.parse_error.101] parse error at 2: syntax error - invalid string: control character must be escaped; last read: '\"<U+001E>'");
                 CHECK_THROWS_WITH(parser_helper("\"\x1f\""), "[json.exception.parse_error.101] parse error at 2: syntax error - invalid string: control character must be escaped; last read: '\"<U+001F>'");
+
+                SECTION("additional test for null byte")
+                {
+                    // The test above for the null byte is wrong, because passing
+                    // a string to the parser only reads int until it encounters
+                    // a null byte. This test inserts the null byte later on and
+                    // uses an iterator range.
+                    std::string s = "\"1\"";
+                    s[1] = '\0';
+                    CHECK_THROWS_AS(json::parse(s.begin(), s.end()), json::parse_error&);
+                    CHECK_THROWS_WITH(json::parse(s.begin(), s.end()), "[json.exception.parse_error.101] parse error at 2: syntax error - invalid string: control character must be escaped; last read: '\"'");
+                }
             }
 
             SECTION("escaped")
diff --git a/test/src/unit-unicode.cpp b/test/src/unit-unicode.cpp
index 9aab0f3c29..b51a1579ed 100644
--- a/test/src/unit-unicode.cpp
+++ b/test/src/unit-unicode.cpp
@@ -924,6 +924,40 @@ TEST_CASE("Unicode", "[hide]")
             }
         }
 
+        SECTION("incorrect sequences")
+        {
+            SECTION("incorrect surrogate values")
+            {
+                CHECK_THROWS_AS(json::parse("\"\\uDC00\\uDC00\""), json::parse_error&);
+                CHECK_THROWS_WITH(json::parse("\"\\uDC00\\uDC00\""),
+                                  "[json.exception.parse_error.101] parse error at 7: syntax error - invalid string: surrogate U+DC00..U+DFFF must follow U+D800..U+DBFF; last read: '\"\\uDC00'");
+
+                CHECK_THROWS_AS(json::parse("\"\\uD7FF\\uDC00\""), json::parse_error&);
+                CHECK_THROWS_WITH(json::parse("\"\\uD7FF\\uDC00\""),
+                                  "[json.exception.parse_error.101] parse error at 13: syntax error - invalid string: surrogate U+DC00..U+DFFF must follow U+D800..U+DBFF; last read: '\"\\uD7FF\\uDC00'");
+
+                CHECK_THROWS_AS(json::parse("\"\\uD800]\""), json::parse_error&);
+                CHECK_THROWS_WITH(json::parse("\"\\uD800]\""),
+                                  "[json.exception.parse_error.101] parse error at 8: syntax error - invalid string: surrogate U+DC00..U+DFFF must be followed by U+DC00..U+DFFF; last read: '\"\\uD800]'");
+
+                CHECK_THROWS_AS(json::parse("\"\\uD800\\v\""), json::parse_error&);
+                CHECK_THROWS_WITH(json::parse("\"\\uD800\\v\""),
+                                  "[json.exception.parse_error.101] parse error at 9: syntax error - invalid string: surrogate U+DC00..U+DFFF must be followed by U+DC00..U+DFFF; last read: '\"\\uD800\\v'");
+
+                CHECK_THROWS_AS(json::parse("\"\\uD800\\u123\""), json::parse_error&);
+                CHECK_THROWS_WITH(json::parse("\"\\uD800\\u123\""),
+                                  "[json.exception.parse_error.101] parse error at 13: syntax error - invalid string: '\\u' must be followed by 4 hex digits; last read: '\"\\uD800\\u123\"'");
+
+                CHECK_THROWS_AS(json::parse("\"\\uD800\\uDBFF\""), json::parse_error&);
+                CHECK_THROWS_WITH(json::parse("\"\\uD800\\uDBFF\""),
+                                  "[json.exception.parse_error.101] parse error at 13: syntax error - invalid string: surrogate U+DC00..U+DFFF must be followed by U+DC00..U+DFFF; last read: '\"\\uD800\\uDBFF'");
+
+                CHECK_THROWS_AS(json::parse("\"\\uD800\\uE000\""), json::parse_error&);
+                CHECK_THROWS_WITH(json::parse("\"\\uD800\\uE000\""),
+                                  "[json.exception.parse_error.101] parse error at 13: syntax error - invalid string: surrogate U+DC00..U+DFFF must be followed by U+DC00..U+DFFF; last read: '\"\\uD800\\uE000'");
+            }
+        }
+
 #if 0
         SECTION("incorrect sequences")
         {