diff --git a/bin/tests/system/legacy/tests.sh b/bin/tests/system/legacy/tests.sh
index 6d1e807511..a7319840dd 100755
--- a/bin/tests/system/legacy/tests.sh
+++ b/bin/tests/system/legacy/tests.sh
@@ -230,6 +230,17 @@ resolution_fails edns512-notcp. || ret=1
 if [ $ret != 0 ]; then echo_i "failed"; fi
 status=`expr $status + $ret`
 
+n=`expr $n + 1`
+echo_i "checking recursive lookup to edns 512 + no tcp server does not cause query loops ($n)"
+ret=0
+sent=`grep -c -F "sending packet to 10.53.0.7" ns1/named.run`
+if [ $sent -ge 10 ]; then
+	echo_i "ns1 sent $sent queries to ns7, expected less than 10"
+	ret=1
+fi
+if [ $ret != 0 ]; then echo_i "failed"; fi
+status=`expr $status + $ret`
+
 $PERL $SYSTEMTESTTOP/stop.pl --use-rndc --port ${CONTROLPORT} legacy ns1
 copy_setports ns1/named2.conf.in ns1/named.conf
 $PERL $SYSTEMTESTTOP/start.pl --noclean --restart --port ${PORT} legacy ns1
diff --git a/lib/dns/resolver.c b/lib/dns/resolver.c
index 9d11349da3..11ef066608 100644
--- a/lib/dns/resolver.c
+++ b/lib/dns/resolver.c
@@ -2956,6 +2956,19 @@ resquery_connected(isc_task_t *task, isc_event_t *event) {
 			 * No route to remote.
 			 */
 			isc_socket_detach(&query->tcpsocket);
+			/*
+			 * Do not query this server again in this fetch context
+			 * if we already tried reducing the advertised EDNS UDP
+			 * payload size to 512 bytes and the server is
+			 * unavailable over TCP.  This prevents query loops
+			 * lasting until the fetch context restart limit is
+			 * reached when attempting to get answers whose size
+			 * exceeds 512 bytes from broken servers.
+			 */
+			if ((query->options & DNS_FETCHOPT_EDNS512) != 0) {
+				add_bad(fctx, query->addrinfo, sevent->result,
+					badns_unreachable);
+			}
 			fctx_cancelquery(&query, NULL, NULL,
 					 true, false);
 			retry = true;