diff --git a/ffmpeg.c b/ffmpeg.c
index a9e5c548fe..5be745e42f 100644
--- a/ffmpeg.c
+++ b/ffmpeg.c
@@ -378,7 +378,7 @@ static int decode_interrupt_cb(void *ctx)
 
 const AVIOInterruptCB int_cb = { decode_interrupt_cb, NULL };
 
-static void exit_program()
+static void exit_program(void)
 {
     int i, j;
 
diff --git a/ffprobe.c b/ffprobe.c
index 31d1a4430a..4fb4982984 100644
--- a/ffprobe.c
+++ b/ffprobe.c
@@ -141,7 +141,7 @@ static const char unit_bit_per_second_str[] = "bit/s";
 static uint64_t *nb_streams_packets;
 static uint64_t *nb_streams_frames;
 
-static void exit_program()
+static void exit_program(void)
 {
     av_dict_free(&fmt_entries_to_show);
 }