diff --git a/src/osx/carbon/msgdlg.cpp b/src/osx/carbon/msgdlg.cpp
index 142581d0f8..7a98a66b81 100644
--- a/src/osx/carbon/msgdlg.cpp
+++ b/src/osx/carbon/msgdlg.cpp
@@ -160,7 +160,7 @@ int wxMessageDialog::ShowModal()
         wxCFStringRef cfCancelString( GetCancelLabel().c_str(), GetFont().GetEncoding() );
 
         wxCFStringRef cfTitle( msgtitle, GetFont().GetEncoding() );
-        wxCFStringRef cfText = msgtext.IsEmpty() ? NULL : wxCFStringRef( msgtext, GetFont().GetEncoding() );
+        wxCFStringRef cfText = msgtext.IsEmpty() ? wxCFStringRef() : wxCFStringRef( msgtext, GetFont().GetEncoding() );
 
         param.movable = true;
         param.flags = 0;