diff --git a/sdl/main.c b/sdl/main.c
index ff68004..0fdf706 100644
--- a/sdl/main.c
+++ b/sdl/main.c
@@ -101,7 +101,7 @@ static int sdl_sound_init()
   return 1;
 }
 
-static void sdl_sound_update(enabled)
+static void sdl_sound_update(int enabled)
 {
   int size = audio_update(soundframe) * 2;