--- Wnn/jutil/wnnkill.c.orig
+++ Wnn/jutil/wnnkill.c
@@ -49,6 +49,9 @@ static char *rcs_id = "$Id: wnnkill.c,v 1.11 1994/06/2
 /*	Version 4.0
  */
 #include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <stdlib.h>
 #include "jllib.h"
 #include "jslib.h"
 #include "jd_sock.h"
@@ -75,7 +78,7 @@ int ocode = (TTY_CCODE + 4);
 int ocode = TTY_HCODE;
 #endif
 
-void
+int
 main(argc, argv)
 int argc;
 char **argv;
