diff --git a/src/proto/os_mswin.pro b/src/proto/os_mswin.pro
index 0d29979..b56ee56 100644
--- a/src/proto/os_mswin.pro
+++ b/src/proto/os_mswin.pro
@@ -21,6 +21,7 @@
 int mch_chdir __ARGS((char *path));
 int can_end_termcap_mode __ARGS((int give_msg));
 int mch_screenmode __ARGS((char_u *arg));
+int mch_icon_load __ARGS((HANDLE *iconp));
 int mch_libcall __ARGS((char_u *libname, char_u *funcname, char_u *argstring, int argint, char_u **string_result, int *number_result));
 void DumpPutS __ARGS((const char *psz));
 int mch_get_winpos __ARGS((int *x, int *y));