diff --git a/src/send_connack.c b/src/send_connack.c
index 629dca64..0891af60 100644
--- a/src/send_connack.c
+++ b/src/send_connack.c
@@ -51,6 +51,18 @@ int send__connack(struct mosquitto_db *db, struct mosquitto *context, int ack, i
 				return rc;
 			}
 		}
+		/* FIXME - disable support until available */
+		rc = mosquitto_property_add_byte(&properties, MQTT_PROP_SHARED_SUB_AVAILABLE, 0);
+		if(rc){
+			mosquitto__free(packet);
+			return rc;
+		}
+		rc = mosquitto_property_add_byte(&properties, MQTT_PROP_SUBSCRIPTION_ID_AVAILABLE, 0);
+		if(rc){
+			mosquitto__free(packet);
+			return rc;
+		}
+
 		proplen = property__get_length_all(properties);
 		varbytes = packet__varint_bytes(proplen);
 		packet->remaining_length += proplen + varbytes;
diff --git a/test/mosq_test.py b/test/mosq_test.py
index 26fea528..a975d833 100644
--- a/test/mosq_test.py
+++ b/test/mosq_test.py
@@ -6,6 +6,8 @@ import struct
 import sys
 import time
 
+import mqtt5_props
+
 def start_broker(filename, cmd=None, port=0, use_conf=False):
     delay = 0.1
 
@@ -359,7 +361,11 @@ def gen_connect(client_id, clean_session=True, keepalive=60, username=None, pass
 
 def gen_connack(resv=0, rc=0, proto_ver=4):
     if proto_ver == 5:
-        packet = struct.pack('!BBBBB', 32, 3, resv, rc, 0);
+        props = mqtt5_props.gen_byte_prop(mqtt5_props.PROP_SHARED_SUB_AVAILABLE, 0)
+        props += mqtt5_props.gen_byte_prop(mqtt5_props.PROP_SUBSCRIPTION_ID_AVAILABLE, 0)
+        props = mqtt5_props.prop_finalise(props)
+
+        packet = struct.pack('!BBBB', 32, 2+len(props), resv, rc) + props
     else:
         packet = struct.pack('!BBBB', 32, 2, resv, rc);