diff --git a/src/proto/popupwin.pro b/src/proto/popupwin.pro
index bfbd883..7608f32 100644
--- a/src/proto/popupwin.pro
+++ b/src/proto/popupwin.pro
@@ -41,7 +41,7 @@
 void f_popup_getpos(typval_T *argvars, typval_T *rettv);
 void f_popup_locate(typval_T *argvars, typval_T *rettv);
 void f_popup_getoptions(typval_T *argvars, typval_T *rettv);
-int error_if_popup_window(void);
+int error_if_popup_window(int also_with_term);
 int error_if_term_popup_window(void);
 void popup_reset_handled(int handled_flag);
 win_T *find_next_popup(int lowest, int handled_flag);