diff --git a/src/window.c b/src/window.c
index f78fcca..f6e6115 100644
--- a/src/window.c
+++ b/src/window.c
@@ -7193,11 +7193,10 @@
 }
 
     win_T *
-win_id2wp(typval_T *argvars)
+win_id2wp(int id)
 {
     win_T	*wp;
     tabpage_T   *tp;
-    int		id = tv_get_number(&argvars[0]);
 
     FOR_ALL_TAB_WINDOWS(tp, wp)
 	if (wp->w_id == id)