diff --git a/plugins/mongodb/index.py b/plugins/mongodb/index.py
index a28adb547..fb7f94bfa 100755
--- a/plugins/mongodb/index.py
+++ b/plugins/mongodb/index.py
@@ -261,7 +261,7 @@ def testData():
     db = client.test
     col = db["demo"]
 
-    rndStr = mw.getRandomString()
+    rndStr = mw.getRandomString(10)
     insert_dict = { "name": "v1", "value": rndStr}
     x = col.insert_one(insert_dict)
     print(x)