diff --git a/src/proto/terminal.pro b/src/proto/terminal.pro
index 8d37db8..e8760d1 100644
--- a/src/proto/terminal.pro
+++ b/src/proto/terminal.pro
@@ -19,6 +19,7 @@
 int term_use_loop(void);
 void term_win_entered(void);
 int terminal_loop(int blocking);
+int may_close_term_popup(void);
 void term_channel_closed(channel_T *ch);
 void term_check_channel_closed_recently(void);
 int term_do_update_window(win_T *wp);