diff --git a/src/proto/os_win32.pro b/src/proto/os_win32.pro
index 5ca85c7..31aa269 100644
--- a/src/proto/os_win32.pro
+++ b/src/proto/os_win32.pro
@@ -1,4 +1,5 @@
 /* os_win32.c */
+HINSTANCE vimLoadLib __ARGS((char *name));
 int dyn_libintl_init __ARGS((char *libname));
 void dyn_libintl_end __ARGS((void));
 void PlatformId __ARGS((void));