diff --git a/src/os2/bitmap.cpp b/src/os2/bitmap.cpp
index 11f601c829..609945ba3c 100644
--- a/src/os2/bitmap.cpp
+++ b/src/os2/bitmap.cpp
@@ -1024,7 +1024,7 @@ HBITMAP wxInvertMask(
                 ,hPSSrc
                 ,4L
                 ,vPoint
-                ,ROP_SRCCOPY
+                ,ROP_SRCINVERT
                 ,BBO_IGNORE
                );