diff --git a/googletest/src/gtest.cc b/googletest/src/gtest.cc
index 30a5cc3f83..66a315e51a 100644
--- a/googletest/src/gtest.cc
+++ b/googletest/src/gtest.cc
@@ -3228,7 +3228,8 @@ static const char* GetAnsiColorCode(GTestColor color) {
     case GTestColor::kYellow:
       return "3";
     default:
-      return nullptr;
+      assert(false);
+      return "9";
   }
 }