diff --git a/etc/emq.conf b/etc/emq.conf
index 4c3ab73c9..5f43eff51 100644
--- a/etc/emq.conf
+++ b/etc/emq.conf
@@ -110,7 +110,7 @@ mqtt.max_packet_size = 64KB
 ## MQTT Connection
 ##--------------------------------------------------------------------
 
-## Force GC: pos_integer
+## Force GC: integer. Value 0 disabled the Force GC.
 mqtt.conn.force_gc_count = 100
 
 ##--------------------------------------------------------------------
diff --git a/src/emqttd_gc.erl b/src/emqttd_gc.erl
index 9261e297e..04cdbf2d5 100644
--- a/src/emqttd_gc.erl
+++ b/src/emqttd_gc.erl
@@ -26,6 +26,7 @@
 conn_max_gc_count() ->
     case emqttd:env(conn_force_gc_count) of
         {ok, I} when I > 0 -> I + rand:uniform(I);
+        {ok, I} when I =< 0 -> undefined;
         undefined -> undefined
     end.