diff -Naur -x '*~' -x '*.orig' -x '*.rej' openssh-7.4p1/sshconnect2.c openssh-7.4p1-gssapi-canohost/sshconnect2.c
--- openssh-7.4p1/sshconnect2.c	2017-01-04 20:10:33.712837132 +0100
+++ openssh-7.4p1-gssapi-canohost/sshconnect2.c	2017-01-04 20:11:59.509465953 +0100
@@ -714,12 +714,15 @@
 	static u_int mech = 0;
 	OM_uint32 min;
 	int ok = 0;
-	const char *gss_host;
+	const char *gss_host = NULL;
 
 	if (options.gss_server_identity)
 		gss_host = options.gss_server_identity;
-	else if (options.gss_trust_dns)
+	else if (options.gss_trust_dns) {
 		gss_host = get_canonical_hostname(active_state, 1);
+		if ( strcmp( gss_host, "UNKNOWN" )  == 0 )
+			gss_host = authctxt->host;
+	}
 	else
 		gss_host = authctxt->host;