diff --git a/peglib.h b/peglib.h
index 14b2628..27f4574 100644
--- a/peglib.h
+++ b/peglib.h
@@ -30,7 +30,7 @@
 #define PEGLIB_NO_CONSTEXPR_SUPPORT
 #elif (_MSC_VER >= 1800)
 // good to go
-#else (_MSC_VER < 1800)
+#else //(_MSC_VER < 1800)
 #error "Requires C+11 support"
 #endif
 #endif