diff --git a/apps/emqx/src/emqx_os_mon.erl b/apps/emqx/src/emqx_os_mon.erl
index 2d928e393..dfce7a255 100644
--- a/apps/emqx/src/emqx_os_mon.erl
+++ b/apps/emqx/src/emqx_os_mon.erl
@@ -53,12 +53,12 @@ start_link() ->
 %%--------------------------------------------------------------------
 
 get_mem_check_interval() ->
-    memsup:get_check_interval() div 1000.
+    memsup:get_check_interval().
 
-set_mem_check_interval(Seconds) when Seconds < 60 ->
+set_mem_check_interval(Seconds) when Seconds < 60000 ->
     memsup:set_check_interval(1);
 set_mem_check_interval(Seconds) ->
-    memsup:set_check_interval(Seconds div 60).
+    memsup:set_check_interval(Seconds div 60000).
 
 get_sysmem_high_watermark() ->
     memsup:get_sysmem_high_watermark().
diff --git a/apps/emqx/src/emqx_schema.erl b/apps/emqx/src/emqx_schema.erl
index 4c0e651f9..8b58d227a 100644
--- a/apps/emqx/src/emqx_schema.erl
+++ b/apps/emqx/src/emqx_schema.erl
@@ -507,10 +507,10 @@ fields("sysmon_vm") ->
     ];
 
 fields("sysmon_os") ->
-    [ {"cpu_check_interval", t(duration(), undefined, 60)}
+    [ {"cpu_check_interval", t(duration(), undefined, "60s")}
     , {"cpu_high_watermark", t(percent(), undefined, "80%")}
     , {"cpu_low_watermark", t(percent(), undefined, "60%")}
-    , {"mem_check_interval", maybe_disabled(duration_s(), 60)}
+    , {"mem_check_interval", maybe_disabled(duration(), "60s")}
     , {"sysmem_high_watermark", t(percent(), undefined, "70%")}
     , {"procmem_high_watermark", t(percent(), undefined, "5%")}
     ];
diff --git a/apps/emqx/test/emqx_os_mon_SUITE.erl b/apps/emqx/test/emqx_os_mon_SUITE.erl
index 6e6d6e861..56c81e9e6 100644
--- a/apps/emqx/test/emqx_os_mon_SUITE.erl
+++ b/apps/emqx/test/emqx_os_mon_SUITE.erl
@@ -26,7 +26,7 @@ all() -> emqx_ct:all(?MODULE).
 init_per_suite(Config) ->
     emqx_config:put([sysmon, os], #{
         cpu_check_interval => 60000,cpu_high_watermark => 0.8,
-        cpu_low_watermark => 0.6,mem_check_interval => 60,
+        cpu_low_watermark => 0.6,mem_check_interval => 60000,
         procmem_high_watermark => 0.05,sysmem_high_watermark => 0.7}),
     application:ensure_all_started(os_mon),
     Config.
@@ -38,11 +38,11 @@ t_api(_) ->
     gen_event:swap_handler(alarm_handler, {emqx_alarm_handler, swap}, {alarm_handler, []}),
     {ok, _} = emqx_os_mon:start_link(),
 
-    ?assertEqual(60, emqx_os_mon:get_mem_check_interval()),
-    ?assertEqual(ok, emqx_os_mon:set_mem_check_interval(30)),
-    ?assertEqual(60, emqx_os_mon:get_mem_check_interval()),
-    ?assertEqual(ok, emqx_os_mon:set_mem_check_interval(122)),
-    ?assertEqual(120, emqx_os_mon:get_mem_check_interval()),
+    ?assertEqual(60000, emqx_os_mon:get_mem_check_interval()),
+    ?assertEqual(ok, emqx_os_mon:set_mem_check_interval(30000)),
+    ?assertEqual(60000, emqx_os_mon:get_mem_check_interval()),
+    ?assertEqual(ok, emqx_os_mon:set_mem_check_interval(122000)),
+    ?assertEqual(120000, emqx_os_mon:get_mem_check_interval()),
 
     ?assertEqual(70, emqx_os_mon:get_sysmem_high_watermark()),
     ?assertEqual(ok, emqx_os_mon:set_sysmem_high_watermark(0.8)),