diff --git a/plugins/mongodb/mongo_lock b/plugins/mongodb/mongo_lock
index 4b94aeca..7b059df7 100755
--- a/plugins/mongodb/mongo_lock
+++ b/plugins/mongodb/mongo_lock
@@ -20,7 +20,10 @@ name = "locked"
 def doData():
     status = getServerStatus()
     if status["version"] >= "2.2.0":
-        ratio = float(status["globalLock"]["lockTime"]) / status["globalLock"]["totalTime"]
+        if status["globalLock"]["lockTime"]["$numberLong"]:
+            ratio = float(status["globalLock"]["lockTime"]["$numberLong"]) / float(status["globalLock"]["totalTime"]["$numberLong"])
+        else:
+            ratio = float(status["globalLock"]["lockTime"]) / status["globalLock"]["totalTime"]
     else:
         ratio = status["globalLock"]["ratio"]
     print name + ".value " + str( 100 * ratio )