diff --git a/appl/push/push.c b/appl/push/push.c
index ca1c508eb..4a4836496 100644
--- a/appl/push/push.c
+++ b/appl/push/push.c
@@ -587,8 +587,10 @@ main(int argc, char **argv)
     if (port == 0)
 #ifdef KRB5
 	port = krb5_getportbyname (context, "kpop", "tcp", 1109);
-#elif defined(KRB5)
+#elif defined(KRB4)
 	port = k_getportbyname ("kpop", "tcp", 1109);
+#else
+#error must define KRB4 or KRB5
 #endif
 
     parse_pobox (argv[0], argv[1],