diff --git a/apps/emqx_management/src/emqx_mgmt_api_banned.erl b/apps/emqx_management/src/emqx_mgmt_api_banned.erl
index 0e6439163..c3cd8e313 100644
--- a/apps/emqx_management/src/emqx_mgmt_api_banned.erl
+++ b/apps/emqx_management/src/emqx_mgmt_api_banned.erl
@@ -59,7 +59,7 @@ create(_Bindings, Params) ->
             {ok, Banned} = pack_banned(NParams),
             ok = emqx_mgmt:create_banned(Banned),
             return({ok, maps:from_list(Params)});
-        {error, Code, Message} -> 
+        {error, Code, Message} ->
             return({error, Code, Message})
     end.
 
@@ -71,7 +71,7 @@ delete(#{as := As, who := Who}, _) ->
         {ok, NParams} ->
             do_delete(get_value(<<"as">>, NParams), get_value(<<"who">>, NParams)),
             return();
-        {error, Code, Message} -> 
+        {error, Code, Message} ->
             return({error, Code, Message})
     end.
 
@@ -105,6 +105,8 @@ validate_params(Params) ->
             {error, ?ERROR8, Msg}
     end.
 
+%% TODO who and reason is undefined - causing dialyzer errors. fix later
+-dialyzer({nowarn_function,pack_banned/1}).
 pack_banned(Params) ->
     Now = erlang:system_time(second),
     do_pack_banned(Params, #banned{by = <<"user">>,
diff --git a/include/emqx.hrl b/include/emqx.hrl
index e13ab8215..a76a86528 100644
--- a/include/emqx.hrl
+++ b/include/emqx.hrl
@@ -145,6 +145,7 @@
 
 -record(banned, {
           who    :: {clientid,  binary()}
+                  | {peerhost, inet:ip_address()}
                   | {username,   binary()}
                   | {ip_address, inet:ip_address()},
           by     :: binary(),
diff --git a/src/emqx.erl b/src/emqx.erl
index deab636d6..b8b8cffbc 100644
--- a/src/emqx.erl
+++ b/src/emqx.erl
@@ -184,7 +184,7 @@ hook(HookPoint, Action, InitArgs) when is_list(InitArgs) ->
 hook(HookPoint, Action, Filter, Priority) ->
     emqx_hooks:add(HookPoint, Action, Filter, Priority).
 
--spec(unhook(emqx_hooks:hookpoint(), fun() | {atom(), atom()} | {atom(), atom(), [any()]}) -> ok).
+-spec(unhook(emqx_hooks:hookpoint(), emqx_hooks:action() | {module(), atom()}) -> ok).
 unhook(HookPoint, Action) ->
     emqx_hooks:del(HookPoint, Action).
 
diff --git a/src/emqx_hooks.erl b/src/emqx_hooks.erl
index ef4245b46..33dca08cb 100644
--- a/src/emqx_hooks.erl
+++ b/src/emqx_hooks.erl
@@ -121,7 +121,7 @@ put(HookPoint, Callback) ->
     end.
 
 %% @doc Unregister a callback.
--spec(del(hookpoint(), function() | {module(), atom()}) -> ok).
+-spec(del(hookpoint(), action() | {module(), atom()}) -> ok).
 del(HookPoint, Action) ->
     gen_server:cast(?SERVER, {del, HookPoint, Action}).
 
diff --git a/src/emqx_types.erl b/src/emqx_types.erl
index dd1bd71a9..b92d457b8 100644
--- a/src/emqx_types.erl
+++ b/src/emqx_types.erl
@@ -127,7 +127,7 @@
                       expiry_interval => non_neg_integer(),
                       atom() => term()
                      }).
--type(clientinfo() :: #{zone         := zone(),
+-type(clientinfo() :: #{zone         := maybe(zone()),
                         protocol     := protocol(),
                         peerhost     := peerhost(),
                         sockport     := non_neg_integer(),