diff --git a/include/extern.h b/include/extern.h
index ecf83601c..8e06bd3fe 100644
--- a/include/extern.h
+++ b/include/extern.h
@@ -1816,6 +1816,7 @@ E void FDECL(beg, (struct monst *));
 E int NDECL(dotalk);
 #ifdef USER_SOUNDS
 E int FDECL(add_sound_mapping, (const char *));
+E void FDECL(play_sound_for_message, (const char *));
 #endif
 
 /* ### sys/msdos/sound.c ### */