diff --git a/fmt/format.h b/fmt/format.h
index 1b727965..4122495d 100644
--- a/fmt/format.h
+++ b/fmt/format.h
@@ -99,7 +99,9 @@ typedef __int64          intmax_t;
 #  define FMT_HAS_GXX_CXX11 1
 # endif
 #else
+# define FMT_GCC_VERSION 0
 # define FMT_GCC_EXTENSION
+# define FMT_HAS_GXX_CXX11 0
 #endif
 
 #if defined(__INTEL_COMPILER)