diff --git a/src/osx/carbon/dataobj.cpp b/src/osx/carbon/dataobj.cpp
index 010b6affd4..e9006fc55e 100644
--- a/src/osx/carbon/dataobj.cpp
+++ b/src/osx/carbon/dataobj.cpp
@@ -703,7 +703,7 @@ bool wxBitmapDataObject::SetData( size_t nSize, const void *pBuf )
     if ((pBuf == NULL) || (nSize == 0))
         return false;
 
-    CGImageRef cgImageRef = 0;
+    CGImageRef cgImageRef = NULL;
 
     CFDataRef data = CFDataCreate( kCFAllocatorDefault, (const UInt8*) pBuf, nSize);
     CGImageSourceRef source = CGImageSourceCreateWithData( data, NULL );