diff --git a/src/eval.c b/src/eval.c
index 08603ca..c30c5d8 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -8587,7 +8587,7 @@
     int	nr = (int)tv_get_number_chk(vp, NULL);
 
     if (nr >= LOWEST_WIN_ID)
-	return win_id2wp(vp);
+	return win_id2wp(tv_get_number(vp));
     return find_win_by_nr(vp, NULL);
 }