diff --git a/src/google/protobuf/message_unittest.inc b/src/google/protobuf/message_unittest.inc
index 73a9740acb..91c88e8c29 100644
--- a/src/google/protobuf/message_unittest.inc
+++ b/src/google/protobuf/message_unittest.inc
@@ -731,6 +731,10 @@ TEST(MESSAGE_TEST_NAME, SupportDeepRecursionLimit) {
   EXPECT_TRUE(p.ParseFromCodedStream(&input));
 }
 
+inline bool IsOptimizeForCodeSize(const Descriptor* descriptor) {
+  return descriptor->file()->options().optimize_for() == FileOptions::CODE_SIZE;
+}
+
 TEST(MESSAGE_TEST_NAME, Swap) {
   UNITTEST::NestedTestAllTypes o;
   constexpr int kDepth = 5;