diff --git a/src/handle_publish.c b/src/handle_publish.c
index 148e7174..8defeb42 100644
--- a/src/handle_publish.c
+++ b/src/handle_publish.c
@@ -163,7 +163,12 @@ int handle__publish(struct mosquitto_db *db, struct mosquitto *context)
 		if(rc) return rc;
 	}else if(topic == NULL && topic_alias){
 		rc = alias__find(context, &topic, topic_alias);
-		if(rc) return rc;
+		if(rc){
+			if(context->protocol == mosq_p_mqtt5){
+				send__disconnect(context, MQTT_RC_TOPIC_ALIAS_INVALID, NULL);
+			}
+			return rc;
+		}
 	}else if(topic == NULL && topic_alias == 0){
 		return MOSQ_ERR_PROTOCOL;
 	}
diff --git a/test/broker/02-subpub-qos0-topic-alias-unknown.py b/test/broker/02-subpub-qos0-topic-alias-unknown.py
new file mode 100755
index 00000000..a79c19e2
--- /dev/null
+++ b/test/broker/02-subpub-qos0-topic-alias-unknown.py
@@ -0,0 +1,37 @@
+#!/usr/bin/env python
+
+# Test whether "topic alias" works to the broker
+# MQTT v5
+
+from mosq_test_helper import *
+
+rc = 1
+keepalive = 60
+connect_packet = mosq_test.gen_connect("sub-test", keepalive=keepalive, proto_ver=5)
+connack_packet = mosq_test.gen_connack(rc=0, proto_ver=5)
+
+props = mqtt5_props.gen_uint16_prop(mqtt5_props.PROP_TOPIC_ALIAS, 3)
+publish1_packet = mosq_test.gen_publish("", qos=0, payload="message", proto_ver=5, properties=props)
+
+disconnect_packet = mosq_test.gen_disconnect(reason_code=148, proto_ver=5)
+
+port = mosq_test.get_port()
+broker = mosq_test.start_broker(filename=os.path.basename(__file__), port=port)
+
+try:
+    sock = mosq_test.do_client_connect(connect_packet, connack_packet, timeout=5, port=port)
+    sock.send(publish1_packet)
+
+    if mosq_test.expect_packet(sock, "disconnect", disconnect_packet):
+        rc = 0
+
+    sock.close()
+finally:
+    broker.terminate()
+    broker.wait()
+    (stdo, stde) = broker.communicate()
+    if rc:
+        print(stde)
+
+exit(rc)
+
diff --git a/test/broker/Makefile b/test/broker/Makefile
index ecf35df3..790f2de3 100644
--- a/test/broker/Makefile
+++ b/test/broker/Makefile
@@ -64,6 +64,7 @@ endif
 	./02-subpub-qos2-receive-maximum-2.py
 	./02-subpub-qos2-pubrec-error.py
 	./02-subpub-qos0-topic-alias.py
+	./02-subpub-qos0-topic-alias-unknown.py
 	./02-unsubscribe-qos0.py
 	./02-unsubscribe-qos1.py
 	./02-unsubscribe-qos2.py
diff --git a/test/broker/ptest.py b/test/broker/ptest.py
index 441946fc..60fdad43 100755
--- a/test/broker/ptest.py
+++ b/test/broker/ptest.py
@@ -47,6 +47,7 @@ tests = [
     (1, './02-subpub-qos2-receive-maximum-2.py'),
     (1, './02-subpub-qos2-pubrec-error.py'),
     (1, './02-subpub-qos0-topic-alias.py'),
+    (1, './02-subpub-qos0-topic-alias-unknown.py'),
     (1, './02-unsubscribe-qos0.py'),
     (1, './02-unsubscribe-qos1.py'),
     (1, './02-unsubscribe-qos2.py'),
diff --git a/test/mosq_test.py b/test/mosq_test.py
index c278cfbb..f3a9d973 100644
--- a/test/mosq_test.py
+++ b/test/mosq_test.py
@@ -483,9 +483,7 @@ def gen_unsubscribe_multiple(mid, topics, proto_ver=4):
     remaining_length = 0
     for t in topics:
         remaining_length += 2+len(t)
-        print(t)
         packet += struct.pack("!H"+str(len(t))+"s", len(t), t)
-        print(packet)
 
     if proto_ver == 5:
         remaining_length += 2+1