diff --git a/apps/emqx_exhook/src/emqx_exhook_mngr.erl b/apps/emqx_exhook/src/emqx_exhook_mngr.erl
index 8c15fc330..1a6e10bf0 100644
--- a/apps/emqx_exhook/src/emqx_exhook_mngr.erl
+++ b/apps/emqx_exhook/src/emqx_exhook_mngr.erl
@@ -195,8 +195,10 @@ handle_info(_Info, State) ->
 
 terminate(_Reason, State = #state{running = Running}) ->
     _ = maps:fold(fun(Name, _, AccIn) ->
-            {ok, NAccIn} = do_unload_server(Name, AccIn),
-            NAccIn
+             case do_unload_server(Name, AccIn) of
+                {ok, NAccIn} -> NAccIn;
+                 _ -> AccIn
+             end
         end, State, Running),
     _ = unload_exhooks(),
     ok.
diff --git a/apps/emqx_exhook/src/emqx_exhook_server.erl b/apps/emqx_exhook/src/emqx_exhook_server.erl
index 94ac4df61..924e5d7ba 100644
--- a/apps/emqx_exhook/src/emqx_exhook_server.erl
+++ b/apps/emqx_exhook/src/emqx_exhook_server.erl
@@ -73,17 +73,13 @@
 
 -export_type([server/0]).
 
--type options() :: #{ url := uri_string:uri_string()
-                    , ssl => map()
-                    }.
-
 -dialyzer({nowarn_function, [inc_metrics/2]}).
 
 %%--------------------------------------------------------------------
 %% Load/Unload APIs
 %%--------------------------------------------------------------------
 
--spec load(binary(), options(), map()) -> {ok, server()} | {error, term()} .
+-spec load(binary(), map(), map()) -> {ok, server()} | {error, term()} .
 load(Name, Opts0, ReqOpts) ->
     {SvrAddr, ClientOpts} = channel_opts(Opts0),
     case emqx_exhook_sup:start_grpc_client_channel(
@@ -268,7 +264,7 @@ match_topic_filter(_, []) ->
 match_topic_filter(TopicName, TopicFilter) ->
     lists:any(fun(F) -> emqx_topic:match(TopicName, F) end, TopicFilter).
 
--spec do_call(string(), atom(), map(), map()) -> {ok, map()} | {error, term()}.
+-spec do_call(binary(), atom(), map(), map()) -> {ok, map()} | {error, term()}.
 do_call(ChannName, Fun, Req, ReqOpts) ->
     Options = ReqOpts#{channel => ChannName},
     ?LOG(debug, "Call ~0p:~0p(~0p, ~0p)", [?PB_CLIENT_MOD, Fun, Req, Options]),
diff --git a/apps/emqx_exhook/src/emqx_exhook_sup.erl b/apps/emqx_exhook/src/emqx_exhook_sup.erl
index ba92e3f96..32f8fa472 100644
--- a/apps/emqx_exhook/src/emqx_exhook_sup.erl
+++ b/apps/emqx_exhook/src/emqx_exhook_sup.erl
@@ -65,13 +65,13 @@ env(Key, Def) ->
 %%--------------------------------------------------------------------
 
 -spec start_grpc_client_channel(
-        string(),
+        binary(),
         uri_string:uri_string(),
         grpc_client:options()) -> {ok, pid()} | {error, term()}.
 start_grpc_client_channel(Name, SvrAddr, Options) ->
     grpc_client_sup:create_channel_pool(Name, SvrAddr, Options).
 
--spec stop_grpc_client_channel(string()) -> ok.
+-spec stop_grpc_client_channel(binary()) -> ok.
 stop_grpc_client_channel(Name) ->
     %% Avoid crash due to hot-upgrade had unloaded
     %% grpc application