diff --git a/src/insexpand.c b/src/insexpand.c
index 779bf5e..1362781 100644
--- a/src/insexpand.c
+++ b/src/insexpand.c
@@ -2994,7 +2994,7 @@
  * one assigned yet.
  */
     static void
-ins_compl_update_sequence_numbers()
+ins_compl_update_sequence_numbers(void)
 {
     int		number = 0;
     compl_T	*match;
@@ -3457,7 +3457,7 @@
  * Get the next set of command-line completions matching "compl_pattern".
  */
     static void
-get_next_cmdline_completion()
+get_next_cmdline_completion(void)
 {
     char_u	**matches;
     int		num_matches;