diff --git a/src/proto/eval.pro b/src/proto/eval.pro
index 37170a2..03c6506 100644
--- a/src/proto/eval.pro
+++ b/src/proto/eval.pro
@@ -111,6 +111,7 @@
 void ex_echohl(exarg_T *eap);
 void ex_execute(exarg_T *eap);
 win_T *find_win_by_nr(typval_T *vp, tabpage_T *tp);
+win_T *find_win_by_nr_or_id(typval_T *vp);
 win_T *find_tabwin(typval_T *wvp, typval_T *tvp);
 void getwinvar(typval_T *argvars, typval_T *rettv, int off);
 void setwinvar(typval_T *argvars, typval_T *rettv, int off);