diff --git a/src/emqx_auth_http_cli.erl b/src/emqx_auth_http_cli.erl
index 25fac43..c56e45d 100644
--- a/src/emqx_auth_http_cli.erl
+++ b/src/emqx_auth_http_cli.erl
@@ -28,11 +28,11 @@
 %%--------------------------------------------------------------------
 
 request(PoolName, get, Path, Headers, Params, Timeout) ->
-    NewPath = Path ++ "?" ++ cow_qs:qs(bin_kw(Params)),
+    NewPath = Path ++ "?" ++ binary_to_list(cow_qs:qs(bin_kw(Params))),
     reply(emqx_http_client:request(get, PoolName, {NewPath, Headers}, Timeout));
 
 request(PoolName, post, Path, Headers, Params, Timeout) ->
-    Body = case proplists:get_value(<<"content_type">>, Headers) of
+    Body = case proplists:get_value(<<"content-type">>, Headers) of
                <<"application/x-www-form-urlencoded">> ->
                    cow_qs:qs(bin_kw(Params));
                <<"application/json">> -> 
diff --git a/test/emqx_auth_http_SUITE.erl b/test/emqx_auth_http_SUITE.erl
index 79c02c0..f9acdc6 100644
--- a/test/emqx_auth_http_SUITE.erl
+++ b/test/emqx_auth_http_SUITE.erl
@@ -66,13 +66,13 @@ set_special_configs(emqx, _Schmea, _Inet) ->
 set_special_configs(emqx_auth_http, Schema, Inet) ->
     ServerAddr = http_server(Schema, Inet),
 
-    AuthReq = #{method => get,
+    AuthReq = #{method => post,
                 url => ServerAddr ++ "/mqtt/auth",
-                content_type => <<"application/x-www-form-urlencoded">>,
+                content_type => <<"application/json">>,
                 params => [{"clientid", "%c"}, {"username", "%u"}, {"password", "%P"}]},
     SuperReq = #{method => post,
                  url => ServerAddr ++ "/mqtt/superuser",
-                 content_type => <<"application/x-www-form-urlencoded">>,
+                 content_type => <<"application/json">>,
                  params => [{"clientid", "%c"}, {"username", "%u"}]},
     AclReq = #{method => post,
                url => ServerAddr ++ "/mqtt/acl",