diff --git a/ext/rg_etc1/rg_etc1.cpp b/ext/rg_etc1/rg_etc1.cpp
index 7a5fce713e..e003f14863 100644
--- a/ext/rg_etc1/rg_etc1.cpp
+++ b/ext/rg_etc1/rg_etc1.cpp
@@ -17,7 +17,9 @@
 //#include <stdio.h>
 #include <math.h>
 
+#ifdef _MSC_VER
 #pragma warning (disable: 4201) //  nonstandard extension used : nameless struct/union
+#endif
 
 #if defined(_DEBUG) || defined(DEBUG)
 #define RG_ETC1_BUILD_DEBUG