diff --git a/apps/iot/src/http_handler/http_host_handler.erl b/apps/iot/src/http_handler/http_host_handler.erl
index dea7b52..95779b6 100644
--- a/apps/iot/src/http_handler/http_host_handler.erl
+++ b/apps/iot/src/http_handler/http_host_handler.erl
@@ -76,9 +76,9 @@ handle_request("POST", "/host/publish_command", _,
                 <<"t_id">> => integer_to_binary(TaskId),
                 <<"t">> => Timeout,
                 <<"ts">> => iot_util:current_time(),
-                <<"m">> => jiffy:encode(Params, [force_utf8])
+                <<"m">> => iolist_to_binary(jiffy:encode(Params, [force_utf8]))
             },
-            BinReply = jiffy:encode(append_service_name(PostParams, Reply), [force_utf8]),
+            BinReply = iolist_to_binary(jiffy:encode(append_service_name(PostParams, Reply), [force_utf8])),
 
             case iot_host:aes_encode(Pid, CommandType, BinReply) of
                 {error, Reason} when is_binary(Reason) ->