diff --git a/ccutil/platform.h b/ccutil/platform.h
index d60a45b601..dd9be87ac6 100644
--- a/ccutil/platform.h
+++ b/ccutil/platform.h
@@ -24,7 +24,9 @@
 
 #define DLLSYM
 #ifdef _WIN32
+#ifndef NOMINMAX
 #define NOMINMAX
+#endif /* NOMINMAX */
 #define WIN32_LEAN_AND_MEAN
 #ifdef __GNUC__
 #define ultoa _ultoa