diff --git a/src/popupwin.c b/src/popupwin.c
index ff877fd..6e1d925 100644
--- a/src/popupwin.c
+++ b/src/popupwin.c
@@ -3309,7 +3309,7 @@
  * Return FALSE when the job has ended.
  */
     int
-error_if_term_popup_window()
+error_if_term_popup_window(void)
 {
     if (WIN_IS_POPUP(curwin) && curbuf->b_term != NULL
 					   && term_job_running(curbuf->b_term))
@@ -3543,7 +3543,7 @@
  * cursor moved far enough.
  */
     void
-popup_check_cursor_pos()
+popup_check_cursor_pos(void)
 {
     win_T *wp;