diff --git a/src/emqx_protocol.erl b/src/emqx_protocol.erl
index 0bedb0927..1f9d19094 100644
--- a/src/emqx_protocol.erl
+++ b/src/emqx_protocol.erl
@@ -290,7 +290,7 @@ process_packet(?CONNECT_PACKET(
                                        properties  = ConnProps,
                                        client_id   = ClientId,
                                        username    = Username,
-                                       password    = Password} = Connect), PState) ->
+                                       password    = Password} = ConnPkt), PState) ->
 
     NewClientId = maybe_use_username_as_clientid(ClientId, Username, PState),
 
@@ -298,7 +298,6 @@ process_packet(?CONNECT_PACKET(
 
     %% TODO: Mountpoint...
     %% Msg -> emqx_mountpoint:mount(MountPoint, Msg)
-    WillMsg = make_will_msg(Connect),
 
     PState1 = set_username(Username,
                            PState#pstate{client_id    = NewClientId,
@@ -307,16 +306,16 @@ process_packet(?CONNECT_PACKET(
                                          clean_start  = CleanStart,
                                          keepalive    = Keepalive,
                                          conn_props   = ConnProps,
-                                         will_msg     = WillMsg,
                                          is_bridge    = IsBridge,
                                          connected_at = os:timestamp()}),
     connack(
-      case check_connect(Connect, PState1) of
+      case check_connect(ConnPkt, PState1) of
           {ok, PState2} ->
               case authenticate(credentials(PState2), Password) of
                   {ok, IsSuper} ->
                       %% Maybe assign a clientId
-                      PState3 = maybe_assign_client_id(PState2#pstate{is_super = IsSuper}),
+                      PState3 = maybe_assign_client_id(PState2#pstate{is_super = IsSuper,
+                                                                      will_msg = make_will_msg(ConnPkt)}),
                       emqx_logger:set_metadata_client_id(PState3#pstate.client_id),
                       %% Open session
                       case try_open_session(PState3) of
@@ -719,14 +718,16 @@ get_property(Name, Props, Default) ->
     maps:get(Name, Props, Default).
 
 make_will_msg(#mqtt_packet_connect{proto_ver   = ProtoVer,
-                                   will_props  = WillProps} = Connect) ->
-    emqx_packet:will_msg(if
-                             ProtoVer =:= ?MQTT_PROTO_V5 ->
-                                 WillDelayInterval = get_property('Will-Delay-Interval', WillProps, 0),
-                                 Connect#mqtt_packet_connect{will_props = set_property('Will-Delay-Interval', WillDelayInterval, WillProps)};
-                             true ->
-                                 Connect
-                         end).
+                                   will_props  = WillProps} = ConnPkt) ->
+    emqx_packet:will_msg(
+        case ProtoVer of
+            ?MQTT_PROTO_V5 ->
+                WillDelayInterval = get_property('Will-Delay-Interval', WillProps, 0),
+                ConnPkt#mqtt_packet_connect{
+                    will_props = set_property('Will-Delay-Interval', WillDelayInterval, WillProps)};
+            _ ->
+                ConnPkt
+        end).
 
 %%------------------------------------------------------------------------------
 %% Check Packet
@@ -735,7 +736,8 @@ make_will_msg(#mqtt_packet_connect{proto_ver   = ProtoVer,
 check_connect(Packet, PState) ->
     run_check_steps([fun check_proto_ver/2,
                      fun check_client_id/2,
-                     fun check_banned/2], Packet, PState).
+                     fun check_banned/2,
+                     fun check_will_topic/2], Packet, PState).
 
 check_proto_ver(#mqtt_packet_connect{proto_ver  = Ver,
                                      proto_name = Name}, _PState) ->
@@ -766,7 +768,7 @@ check_client_id(#mqtt_packet_connect{client_id = ClientId}, #pstate{zone = Zone}
         false -> {error, ?RC_CLIENT_IDENTIFIER_NOT_VALID}
     end.
 
-check_banned(_Connect, #pstate{enable_ban = false}) ->
+check_banned(_ConnPkt, #pstate{enable_ban = false}) ->
     ok;
 check_banned(#mqtt_packet_connect{client_id = ClientId, username = Username},
              #pstate{peername = Peername}) ->
@@ -777,6 +779,26 @@ check_banned(#mqtt_packet_connect{client_id = ClientId, username = Username},
         false -> ok
     end.
 
+check_will_topic(#mqtt_packet_connect{will_flag = false}, _PState) ->
+    ok;
+check_will_topic(#mqtt_packet_connect{will_topic = WillTopic} = ConnPkt, PState) ->
+    try emqx_topic:validate(WillTopic) of
+        true -> check_will_acl(ConnPkt, PState)
+    catch error : _Error ->
+            {error, ?RC_TOPIC_NAME_INVALID}
+    end.
+
+check_will_acl(_ConnPkt, #pstate{enable_acl = EnableAcl})
+  when not EnableAcl ->
+    ok;
+check_will_acl(#mqtt_packet_connect{will_topic = WillTopic}, PState) ->
+    case emqx_access_control:check_acl(credentials(PState), publish, WillTopic) of
+        allow -> ok;
+        deny ->
+            ?LOG(warning, "Cannot publish will message to ~p for acl checking failed", [WillTopic]),
+            {error, ?RC_UNSPECIFIED_ERROR}
+    end.
+
 check_publish(Packet, PState) ->
     run_check_steps([fun check_pub_caps/2,
                      fun check_pub_acl/2], Packet, PState).
@@ -902,25 +924,29 @@ flag(true)  -> 1.
 %% Execute actions in case acl deny
 
 do_acl_deny_action(?PUBLISH_PACKET(?QOS_0, _Topic, _PacketId, _Payload),
-                   ?RC_NOT_AUTHORIZED, PState = #pstate{acl_deny_action = disconnect}) ->
-    {error, ?RC_NOT_AUTHORIZED, PState};
+                   ?RC_NOT_AUTHORIZED, PState = #pstate{proto_ver = ProtoVer,
+                                                        acl_deny_action = disconnect}) ->
+    {error, emqx_reason_codes:name(?RC_NOT_AUTHORIZED, ProtoVer), PState};
 
 do_acl_deny_action(?PUBLISH_PACKET(?QOS_1, _Topic, _PacketId, _Payload),
-                   ?RC_NOT_AUTHORIZED, PState = #pstate{acl_deny_action = disconnect}) ->
+                   ?RC_NOT_AUTHORIZED, PState = #pstate{proto_ver = ProtoVer,
+                                                        acl_deny_action = disconnect}) ->
     deliver({disconnect, ?RC_NOT_AUTHORIZED}, PState),
-    {error, ?RC_NOT_AUTHORIZED, PState};
+    {error, emqx_reason_codes:name(?RC_NOT_AUTHORIZED, ProtoVer), PState};
 
 do_acl_deny_action(?PUBLISH_PACKET(?QOS_2, _Topic, _PacketId, _Payload),
-                   ?RC_NOT_AUTHORIZED, PState = #pstate{acl_deny_action = disconnect}) ->
+                   ?RC_NOT_AUTHORIZED, PState = #pstate{proto_ver = ProtoVer,
+                                                        acl_deny_action = disconnect}) ->
     deliver({disconnect, ?RC_NOT_AUTHORIZED}, PState),
-    {error, ?RC_NOT_AUTHORIZED, PState};
+    {error, emqx_reason_codes:name(?RC_NOT_AUTHORIZED, ProtoVer), PState};
 
 do_acl_deny_action(?SUBSCRIBE_PACKET(_PacketId, _Properties, _RawTopicFilters),
-                   ReasonCodes, PState = #pstate{acl_deny_action = disconnect}) ->
+                   ReasonCodes, PState = #pstate{proto_ver = ProtoVer,
+                                                 acl_deny_action = disconnect}) ->
     case lists:member(?RC_NOT_AUTHORIZED, ReasonCodes) of
         true ->
             deliver({disconnect, ?RC_NOT_AUTHORIZED}, PState),
-            {error, ?RC_NOT_AUTHORIZED, PState};
+            {error, emqx_reason_codes:name(?RC_NOT_AUTHORIZED, ProtoVer), PState};
         false ->
             {ok, PState}
     end;
diff --git a/src/emqx_reason_codes.erl b/src/emqx_reason_codes.erl
index 3dc73a5d5..c6bdd849d 100644
--- a/src/emqx_reason_codes.erl
+++ b/src/emqx_reason_codes.erl
@@ -133,6 +133,7 @@ compat(connack, 16#89) -> ?CONNACK_SERVER;
 compat(connack, 16#8A) -> ?CONNACK_AUTH;
 compat(connack, 16#8B) -> ?CONNACK_SERVER;
 compat(connack, 16#8C) -> ?CONNACK_AUTH;
+compat(connack, 16#90) -> ?CONNACK_SERVER;
 compat(connack, 16#97) -> ?CONNACK_SERVER;
 compat(connack, 16#9C) -> ?CONNACK_SERVER;
 compat(connack, 16#9D) -> ?CONNACK_SERVER;
diff --git a/test/emqx_protocol_SUITE.erl b/test/emqx_protocol_SUITE.erl
index 387be3053..38d1001d3 100644
--- a/test/emqx_protocol_SUITE.erl
+++ b/test/emqx_protocol_SUITE.erl
@@ -35,13 +35,17 @@
 
 all() ->
     [
+     {group, mqtt_common},
      {group, mqttv4},
      {group, mqttv5},
      {group, acl}
     ].
 
 groups() ->
-    [{mqttv4,
+    [{mqtt_common,
+      [sequence],
+      [will_check]},
+     {mqttv4,
       [sequence],
       [connect_v4,
        subscribe_v4]},
@@ -53,7 +57,6 @@ groups() ->
       [sequence],
       [acl_deny_action]}].
 
-
 init_per_suite(Config) ->
     [start_apps(App, SchemaFile, ConfigFile) ||
         {App, SchemaFile, ConfigFile}
@@ -436,6 +439,39 @@ acl_deny_action(_) ->
     emqx_zone:set_env(external, acl_deny_action, ignore),
     ok.
 
+will_check(_) ->
+    process_flag(trap_exit, true),
+    will_topic_check(0),
+    will_acl_check(0).
+
+will_topic_check(QoS) ->
+    {ok, Client} = emqx_client:start_link([{username, <<"emqx">>},
+                                           {will_flag, true},
+                                           {will_topic, <<"">>},
+                                           {will_payload, <<"I have died">>},
+                                           {will_qos, QoS}]),
+    try emqx_client:connect(Client) of
+        _ ->
+            ok
+    catch
+        exit : _Reason ->
+            false = is_process_alive(Client)
+    end.
+
+will_acl_check(QoS) ->
+    {ok, Client} = emqx_client:start_link([{username, <<"emqx">>},
+                                           {will_flag, true},
+                                           {will_topic, <<"acl_deny_action">>},
+                                           {will_payload, <<"I have died">>},
+                                           {will_qos, QoS}]),
+    try emqx_client:connect(Client) of
+        _ ->
+            ok
+    catch
+        exit : _Reason ->
+            false = is_process_alive(Client)
+    end.
+
 acl_deny_do_disconnect(publish, QoS, Topic) ->
     {ok, Client} = emqx_client:start_link([{username, <<"emqx">>}]),
     {ok, _} = emqx_client:connect(Client),