diff --git a/lib/krb5/test_kuserok.c b/lib/krb5/test_kuserok.c
index b48ecefb0..54da41658 100644
--- a/lib/krb5/test_kuserok.c
+++ b/lib/krb5/test_kuserok.c
@@ -32,6 +32,7 @@
 
 #include "krb5_locl.h"
 #include <getarg.h>
+#include <err.h>
 
 RCSID("$Id$");