--- mstools/samples/output/output.c	2018/08/09 18:20:01	1.1.1.1
+++ mstools/samples/output/output.c	2018/08/09 18:20:45	1.1.1.2
@@ -172,7 +172,7 @@ LONG APIENTRY MainWndProc(
 		DialogBox(hInst,
 		    "AboutBox",
 		    hWnd,
-		    (WNDPROC)lpProcAbout);
+		    lpProcAbout);
 
 		FreeProcInstance(lpProcAbout);
 		break;