diff --git a/conformance/binary_json_conformance_suite.cc b/conformance/binary_json_conformance_suite.cc
index 9a66baebdf..a91b746672 100644
--- a/conformance/binary_json_conformance_suite.cc
+++ b/conformance/binary_json_conformance_suite.cc
@@ -1769,6 +1769,38 @@ void BinaryAndJsonConformanceSuiteImpl<
         absl::StrCat("IgnoreUnknownEnumStringValue", test_case.enum_location),
         RECOMMENDED, test_case.input_json, "");
   }
+
+  // This test is similar to "InRepeatedField" from above, but it highlights the
+  // potentially unexpected behavior in an array with mixed known and unknown
+  // enum string values.
+  RunValidJsonIgnoreUnknownTest("IgnoreUnknownEnumStringValueInRepeatedPart",
+                                RECOMMENDED,
+                                R"json({
+    "repeated_nested_enum": [
+      "FOO",
+      "UNKNOWN_ENUM_VALUE",
+      "FOO"
+    ]})json",
+                                R"(
+    repeated_nested_enum: FOO
+    repeated_nested_enum: FOO
+  )");
+
+  // This test is similar to "InMapValue" from above with mixture of known and
+  // unknown enum string values in the map.
+  RunValidJsonIgnoreUnknownTest("IgnoreUnknownEnumStringValueInMapPart",
+                                RECOMMENDED,
+                                R"json({
+    "map_string_nested_enum": {
+      "key1": "FOO",
+      "key2": "UNKNOWN_ENUM_VALUE"
+    }})json",
+                                R"(
+    map_string_nested_enum: {
+      key: "key1"
+      value: FOO
+    }
+  )");
 }
 
 template <typename MessageType>
diff --git a/conformance/failure_list_cpp.txt b/conformance/failure_list_cpp.txt
index 785ebc92a2..0f4e10ff63 100644
--- a/conformance/failure_list_cpp.txt
+++ b/conformance/failure_list_cpp.txt
@@ -29,6 +29,10 @@ Recommended.Proto3.JsonInput.FieldNameNotQuoted
 Recommended.Editions_Proto3.JsonInput.FieldNameNotQuoted
 Recommended.Proto3.JsonInput.IgnoreUnknownEnumStringValueInMapValue.ProtobufOutput
 Recommended.Editions_Proto3.JsonInput.IgnoreUnknownEnumStringValueInMapValue.ProtobufOutput
+Recommended.Editions_Proto2.JsonInput.IgnoreUnknownEnumStringValueInMapPart.ProtobufOutput
+Recommended.Editions_Proto3.JsonInput.IgnoreUnknownEnumStringValueInMapPart.ProtobufOutput
+Recommended.Proto2.JsonInput.IgnoreUnknownEnumStringValueInMapPart.ProtobufOutput
+Recommended.Proto3.JsonInput.IgnoreUnknownEnumStringValueInMapPart.ProtobufOutput
 Recommended.Proto3.JsonInput.MapFieldValueIsNull
 Recommended.Editions_Proto3.JsonInput.MapFieldValueIsNull
 Recommended.Proto3.JsonInput.RepeatedFieldMessageElementIsNull
@@ -104,4 +108,4 @@ Recommended.Proto2.JsonInput.StringFieldUppercaseEscapeLetter
 Recommended.Proto2.JsonInput.TrailingCommaInAnObject
 Recommended.Proto2.JsonInput.TrailingCommaInAnObjectWithNewlines
 Recommended.Proto2.JsonInput.TrailingCommaInAnObjectWithSpace
-Recommended.Proto2.JsonInput.TrailingCommaInAnObjectWithSpaceCommaSpace
\ No newline at end of file
+Recommended.Proto2.JsonInput.TrailingCommaInAnObjectWithSpaceCommaSpace
diff --git a/conformance/failure_list_php.txt b/conformance/failure_list_php.txt
index 4876e10ba4..5c09f3fc2f 100644
--- a/conformance/failure_list_php.txt
+++ b/conformance/failure_list_php.txt
@@ -7,6 +7,14 @@ Recommended.Proto3.JsonInput.BytesFieldBase64Url.ProtobufOutput
 Recommended.Proto3.JsonInput.FieldMaskInvalidCharacter
 Recommended.Proto3.JsonInput.IgnoreUnknownEnumStringValueInMapValue.ProtobufOutput
 Recommended.Proto3.JsonInput.IgnoreUnknownEnumStringValueInRepeatedField.ProtobufOutput
+Recommended.Editions_Proto2.JsonInput.IgnoreUnknownEnumStringValueInRepeatedPart.ProtobufOutput
+Recommended.Editions_Proto3.JsonInput.IgnoreUnknownEnumStringValueInRepeatedPart.ProtobufOutput
+Recommended.Proto2.JsonInput.IgnoreUnknownEnumStringValueInRepeatedPart.ProtobufOutput
+Recommended.Proto3.JsonInput.IgnoreUnknownEnumStringValueInRepeatedPart.ProtobufOutput
+Recommended.Editions_Proto2.JsonInput.IgnoreUnknownEnumStringValueInMapPart.ProtobufOutput
+Recommended.Editions_Proto3.JsonInput.IgnoreUnknownEnumStringValueInMapPart.ProtobufOutput
+Recommended.Proto2.JsonInput.IgnoreUnknownEnumStringValueInMapPart.ProtobufOutput
+Recommended.Proto3.JsonInput.IgnoreUnknownEnumStringValueInMapPart.ProtobufOutput
 Recommended.Proto3.ProtobufInput.ValidDataOneofBinary.MESSAGE.Merge.ProtobufOutput
 Required.Proto2.JsonInput.StoresDefaultPrimitive.Validator
 Required.Proto3.JsonInput.DoubleFieldTooSmall
diff --git a/conformance/failure_list_python.txt b/conformance/failure_list_python.txt
index 6a483601cb..fd10110dc3 100644
--- a/conformance/failure_list_python.txt
+++ b/conformance/failure_list_python.txt
@@ -10,3 +10,11 @@ Recommended.Editions_Proto2.JsonInput.IgnoreUnknownEnumStringValueInRepeatedFiel
 Recommended.Proto2.JsonInput.IgnoreUnknownEnumStringValueInMapValue.ProtobufOutput
 Recommended.Proto2.JsonInput.IgnoreUnknownEnumStringValueInOptionalField.ProtobufOutput
 Recommended.Proto2.JsonInput.IgnoreUnknownEnumStringValueInRepeatedField.ProtobufOutput
+Recommended.Editions_Proto2.JsonInput.IgnoreUnknownEnumStringValueInRepeatedPart.ProtobufOutput
+Recommended.Editions_Proto3.JsonInput.IgnoreUnknownEnumStringValueInRepeatedPart.ProtobufOutput
+Recommended.Proto2.JsonInput.IgnoreUnknownEnumStringValueInRepeatedPart.ProtobufOutput
+Recommended.Proto3.JsonInput.IgnoreUnknownEnumStringValueInRepeatedPart.ProtobufOutput
+Recommended.Editions_Proto2.JsonInput.IgnoreUnknownEnumStringValueInMapPart.ProtobufOutput
+Recommended.Editions_Proto3.JsonInput.IgnoreUnknownEnumStringValueInMapPart.ProtobufOutput
+Recommended.Proto2.JsonInput.IgnoreUnknownEnumStringValueInMapPart.ProtobufOutput
+Recommended.Proto3.JsonInput.IgnoreUnknownEnumStringValueInMapPart.ProtobufOutput
diff --git a/conformance/failure_list_python_cpp.txt b/conformance/failure_list_python_cpp.txt
index c0e2f16fa3..3d5ff185f6 100644
--- a/conformance/failure_list_python_cpp.txt
+++ b/conformance/failure_list_python_cpp.txt
@@ -17,4 +17,12 @@ Recommended.Editions_Proto2.JsonInput.IgnoreUnknownEnumStringValueInOptionalFiel
 Recommended.Editions_Proto2.JsonInput.IgnoreUnknownEnumStringValueInRepeatedField.ProtobufOutput
 Recommended.Proto2.JsonInput.IgnoreUnknownEnumStringValueInMapValue.ProtobufOutput
 Recommended.Proto2.JsonInput.IgnoreUnknownEnumStringValueInOptionalField.ProtobufOutput
-Recommended.Proto2.JsonInput.IgnoreUnknownEnumStringValueInRepeatedField.ProtobufOutput
\ No newline at end of file
+Recommended.Proto2.JsonInput.IgnoreUnknownEnumStringValueInRepeatedField.ProtobufOutput
+Recommended.Editions_Proto2.JsonInput.IgnoreUnknownEnumStringValueInRepeatedPart.ProtobufOutput
+Recommended.Editions_Proto3.JsonInput.IgnoreUnknownEnumStringValueInRepeatedPart.ProtobufOutput
+Recommended.Proto2.JsonInput.IgnoreUnknownEnumStringValueInRepeatedPart.ProtobufOutput
+Recommended.Proto3.JsonInput.IgnoreUnknownEnumStringValueInRepeatedPart.ProtobufOutput
+Recommended.Editions_Proto2.JsonInput.IgnoreUnknownEnumStringValueInMapPart.ProtobufOutput
+Recommended.Editions_Proto3.JsonInput.IgnoreUnknownEnumStringValueInMapPart.ProtobufOutput
+Recommended.Proto2.JsonInput.IgnoreUnknownEnumStringValueInMapPart.ProtobufOutput
+Recommended.Proto3.JsonInput.IgnoreUnknownEnumStringValueInMapPart.ProtobufOutput
diff --git a/conformance/failure_list_python_upb.txt b/conformance/failure_list_python_upb.txt
index b656120eeb..7a90ac8d35 100644
--- a/conformance/failure_list_python_upb.txt
+++ b/conformance/failure_list_python_upb.txt
@@ -9,4 +9,12 @@ Recommended.Proto2.JsonInput.IgnoreUnknownEnumStringValueInOptionalField.Protobu
 Recommended.Proto2.JsonInput.IgnoreUnknownEnumStringValueInRepeatedField.ProtobufOutput
 Recommended.Editions_Proto2.JsonInput.IgnoreUnknownEnumStringValueInMapValue.ProtobufOutput
 Recommended.Editions_Proto2.JsonInput.IgnoreUnknownEnumStringValueInOptionalField.ProtobufOutput
-Recommended.Editions_Proto2.JsonInput.IgnoreUnknownEnumStringValueInRepeatedField.ProtobufOutput
\ No newline at end of file
+Recommended.Editions_Proto2.JsonInput.IgnoreUnknownEnumStringValueInRepeatedField.ProtobufOutput
+Recommended.Editions_Proto2.JsonInput.IgnoreUnknownEnumStringValueInRepeatedPart.ProtobufOutput
+Recommended.Editions_Proto3.JsonInput.IgnoreUnknownEnumStringValueInRepeatedPart.ProtobufOutput
+Recommended.Proto2.JsonInput.IgnoreUnknownEnumStringValueInRepeatedPart.ProtobufOutput
+Recommended.Proto3.JsonInput.IgnoreUnknownEnumStringValueInRepeatedPart.ProtobufOutput
+Recommended.Editions_Proto2.JsonInput.IgnoreUnknownEnumStringValueInMapPart.ProtobufOutput
+Recommended.Editions_Proto3.JsonInput.IgnoreUnknownEnumStringValueInMapPart.ProtobufOutput
+Recommended.Proto2.JsonInput.IgnoreUnknownEnumStringValueInMapPart.ProtobufOutput
+Recommended.Proto3.JsonInput.IgnoreUnknownEnumStringValueInMapPart.ProtobufOutput