diff --git a/gcc/fixinc/tests/base/types/vxTypesBase.h b/gcc/fixinc/tests/base/types/vxTypesBase.h
index 7d7a434c8f7..76a9338d970 100644
--- a/gcc/fixinc/tests/base/types/vxTypesBase.h
+++ b/gcc/fixinc/tests/base/types/vxTypesBase.h
@@ -19,10 +19,12 @@ typedef unsigned int size_t;
 #define _GCC_PTRDIFF_T
 typedef long ptrdiff_t;
 #endif
+#ifndef __cplusplus
 #ifndef _GCC_WCHAR_T
 #define _GCC_WCHAR_T
 typedef unsigned short wchar_t;
 #endif
+#endif
 #endif /* __GNUC_TYPEOF_FEATURE_BROKEN_USE_DEFAULT_UNTIL_FIXED__ */
 
 #endif  /* VXWORKS_GCC_PROBLEM_CHECK */