diff --git a/include/extern.h b/include/extern.h
index a6347c17a..34feb78e3 100644
--- a/include/extern.h
+++ b/include/extern.h
@@ -174,7 +174,7 @@ E boolean NDECL(status_hilite_menu);
 /* ### cmd.c ### */
 
 E char NDECL(randomkey);
-E void FDECL(random_response, (char * buf, int size));
+E void FDECL(random_response, (char *, int));
 E int NDECL(doconduct);
 E int NDECL(domonability);
 E char FDECL(cmd_from_func, (int NDECL((*))));