diff --git a/src/mac/carbon/dccg.cpp b/src/mac/carbon/dccg.cpp
index a91add9cef..eaaa2f179c 100755
--- a/src/mac/carbon/dccg.cpp
+++ b/src/mac/carbon/dccg.cpp
@@ -24,9 +24,11 @@
 #include "wx/log.h"
 
 
-#if __MSL__ >= 0x6000
-#include "math.h"
-using namespace std ;
+#ifdef __MSL__
+    #if __MSL__ >= 0x6000
+        #include "math.h"
+        using namespace std ;
+    #endif
 #endif
 
 #include "wx/mac/private.h"