diff --git a/src/osx/carbon/graphics.cpp b/src/osx/carbon/graphics.cpp
index 7d60feaefc..b018e6a38c 100644
--- a/src/osx/carbon/graphics.cpp
+++ b/src/osx/carbon/graphics.cpp
@@ -1314,7 +1314,7 @@ public:
 
     virtual void * GetNativeContext();
 
-    bool SetLogicalFunction( int function );
+    bool SetLogicalFunction( wxRasterOperationMode function );
     //
     // transformation
     //