--- mstools/samples/getsys/getsys.h	2018/08/09 18:20:48	1.1
+++ mstools/samples/getsys/getsys.h	2018/08/09 18:21:48	1.1.1.2
@@ -2,7 +2,7 @@
 
 
 /* function prototypes.  Window procedures first. */
-LRESULT MainDlgProc(HWND, UINT, WPARAM, LPARAM);
+LRESULT CALLBACK MainDlgProc(HWND, UINT, WPARAM, LPARAM);
 
 VOID doSysColors (HWND);
 VOID doInfo      (HWND);