diff --git a/include/emqx.hrl b/include/emqx.hrl
index e206ad51d..7afe009a2 100644
--- a/include/emqx.hrl
+++ b/include/emqx.hrl
@@ -152,6 +152,7 @@
 %%--------------------------------------------------------------------
 %% Banned
 %%--------------------------------------------------------------------
+
 -type(banned_who() ::  {client_id,  binary()}
                      | {username,   binary()}
                      | {ip_address, inet:ip_address()}).
@@ -165,3 +166,13 @@
         }).
 
 -endif.
+
+%%--------------------------------------------------------------------
+%% Compatible with Windows
+%%--------------------------------------------------------------------
+
+-define(compat_windows(Expression, Default),
+        case os:type() of
+            {win32, nt} -> Default;
+            _Unix -> Expression
+        end).
diff --git a/src/emqx_message.erl b/src/emqx_message.erl
index 23ddd69d4..e2394a5df 100644
--- a/src/emqx_message.erl
+++ b/src/emqx_message.erl
@@ -188,8 +188,24 @@ update_expiry(Msg) -> Msg.
 
 %% @doc Message to map
 -spec(to_map(emqx_types:message()) -> map()).
-to_map(Msg) ->
-    maps:from_list(to_list(Msg)).
+to_map(#message{
+          id = Id,
+          qos = QoS,
+          from = From,
+          flags = Flags,
+          headers = Headers,
+          topic = Topic,
+          payload = Payload,
+          timestamp = Timestamp
+        }) ->
+    #{id => Id,
+      qos => QoS,
+      from => From,
+      flags => Flags,
+      headers => Headers,
+      topic => Topic,
+      payload => Payload,
+      timestamp => Timestamp}.
 
 %% @doc Message to tuple list
 -spec(to_list(emqx_types:message()) -> map()).
diff --git a/src/emqx_os_mon.erl b/src/emqx_os_mon.erl
index 21624c079..967f94ea2 100644
--- a/src/emqx_os_mon.erl
+++ b/src/emqx_os_mon.erl
@@ -47,10 +47,7 @@
 
 -define(OS_MON, ?MODULE).
 
--define(compat_windows(Expression), case os:type() of
-                                        {win32, nt} -> windows;
-                                        _Unix -> Expression
-                                    end).
+-include("emqx.hrl").
 
 %%------------------------------------------------------------------------------
 %% API
@@ -100,7 +97,7 @@ set_procmem_high_watermark(Float) ->
 %%------------------------------------------------------------------------------
 
 init([Opts]) ->
-    _ = ?compat_windows(cpu_sup:util()),
+    _ = ?compat_windows(cpu_sup:util(), windows),
     set_mem_check_interval(proplists:get_value(mem_check_interval, Opts, 60)),
     set_sysmem_high_watermark(proplists:get_value(sysmem_high_watermark, Opts, 0.70)),
     set_procmem_high_watermark(proplists:get_value(procmem_high_watermark, Opts, 0.05)),
@@ -135,7 +132,7 @@ handle_info({timeout, Timer, check}, State = #{timer := Timer,
                                                cpu_high_watermark := CPUHighWatermark,
                                                cpu_low_watermark := CPULowWatermark,
                                                is_cpu_alarm_set := IsCPUAlarmSet}) ->
-    case ?compat_windows(cpu_sup:util()) of
+    case ?compat_windows(cpu_sup:util(), windows) of
         0 ->
             {noreply, State#{timer := undefined}};
         {error, Reason} ->
diff --git a/src/emqx_session.erl b/src/emqx_session.erl
index b4a3032ce..17d07ca0a 100644
--- a/src/emqx_session.erl
+++ b/src/emqx_session.erl
@@ -214,7 +214,7 @@ attrs(#state{clean_start = CleanStart,
      {binding, binding(ConnPid)},
      {client_id, ClientId},
      {username, Username},
-     {expiry_interval, ExpiryInterval div 1000},
+     {expiry_interval, ExpiryInterval},
      {created_at, CreatedAt}].
 
 -spec(stats(spid() | #state{}) -> list({atom(), non_neg_integer()})).
diff --git a/src/emqx_vm.erl b/src/emqx_vm.erl
index fcc9b3067..46c038732 100644
--- a/src/emqx_vm.erl
+++ b/src/emqx_vm.erl
@@ -159,6 +159,8 @@
                       sndbuf,
                       tos]).
 
+-include("emqx.hrl").
+
 schedulers() ->
     erlang:system_info(schedulers).
 
@@ -167,9 +169,9 @@ microsecs() ->
     (Mega * 1000000 + Sec) * 1000000 + Micro.
 
 loads() ->
-    [{load1,  ftos(cpu_sup:avg1()/256)},
-     {load5,  ftos(cpu_sup:avg5()/256)},
-     {load15, ftos(cpu_sup:avg15()/256)}].
+    [{load1,  ftos(?compat_windows(cpu_sup:avg1()/256, 0.0))},
+     {load5,  ftos(?compat_windows(cpu_sup:avg5()/256, 0.0))},
+     {load15, ftos(?compat_windows(cpu_sup:avg15()/256, 0.0))}].
 
 get_system_info() ->
     [{Key, format_system_info(Key, get_system_info(Key))} || Key <- ?SYSTEM_INFO].