diff --git a/src/emqx_mod_sup.erl b/src/emqx_mod_sup.erl
index cb6e86130..9685bc760 100644
--- a/src/emqx_mod_sup.erl
+++ b/src/emqx_mod_sup.erl
@@ -40,7 +40,7 @@
 start_link() ->
     supervisor:start_link({local, ?MODULE}, ?MODULE, []).
 
-start_child(ChildSpec) when is_tuple(ChildSpec) ->
+start_child(ChildSpec) when is_map(ChildSpec) ->
     supervisor:start_child(?MODULE, ChildSpec).
 
 start_child(Mod, Type) when is_atom(Mod) andalso is_atom(Type) ->
diff --git a/test/emqx_mod_sup_SUITE.erl b/test/emqx_mod_sup_SUITE.erl
new file mode 100644
index 000000000..fac49363e
--- /dev/null
+++ b/test/emqx_mod_sup_SUITE.erl
@@ -0,0 +1,51 @@
+%%--------------------------------------------------------------------
+%% Copyright (c) 2019 EMQ Technologies Co., Ltd. All Rights Reserved.
+%%
+%% Licensed under the Apache License, Version 2.0 (the "License");
+%% you may not use this file except in compliance with the License.
+%% You may obtain a copy of the License at
+%%
+%%     http://www.apache.org/licenses/LICENSE-2.0
+%%
+%% Unless required by applicable law or agreed to in writing, software
+%% distributed under the License is distributed on an "AS IS" BASIS,
+%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+%% See the License for the specific language governing permissions and
+%% limitations under the License.
+%%--------------------------------------------------------------------
+
+-module(emqx_mod_sup_SUITE).
+
+-compile(export_all).
+-compile(nowarn_export_all).
+
+-include_lib("eunit/include/eunit.hrl").
+
+all() -> emqx_ct:all(?MODULE).
+
+%%--------------------------------------------------------------------
+%% Test cases
+%%--------------------------------------------------------------------
+
+t_start(_) ->
+    {ok, _} = emqx_mod_sup:start_link(),
+    ?assertEqual([], supervisor:which_children(emqx_mod_sup)).
+
+t_start_child(_) ->
+    %% Set the emqx_mod_sup child with emqx_hooks for test
+    Mod = emqx_hooks,
+    Spec = #{id => Mod,
+             start => {Mod, start_link, []},
+             restart => permanent,
+             shutdown => 5000,
+             type => worker,
+             modules => [Mod]},
+
+    {ok, _} = emqx_mod_sup:start_link(),
+    {ok, _} = emqx_mod_sup:start_child(Mod, worker),
+    {error, {already_started, _}} = emqx_mod_sup:start_child(Spec),
+
+    ok = emqx_mod_sup:stop_child(Mod),
+    {error, not_found} = emqx_mod_sup:stop_child(Mod),
+    ok.
+