diff --git a/common/lib/xmodule/xmodule/contentstore/mongo.py b/common/lib/xmodule/xmodule/contentstore/mongo.py
index 8482de5e27..bf3fa0645f 100644
--- a/common/lib/xmodule/xmodule/contentstore/mongo.py
+++ b/common/lib/xmodule/xmodule/contentstore/mongo.py
@@ -485,7 +485,7 @@ class MongoContentStore(ContentStore):
             [
                 ('_id.org', pymongo.ASCENDING),
                 ('_id.course', pymongo.ASCENDING),
-                ('display_name', pymongo.ASCENDING)
+                ('displayname', pymongo.ASCENDING)
             ],
             sparse=True,
             background=True
@@ -505,7 +505,7 @@ class MongoContentStore(ContentStore):
             [
                 ('content_son.org', pymongo.ASCENDING),
                 ('content_son.course', pymongo.ASCENDING),
-                ('display_name', pymongo.ASCENDING)
+                ('displayname', pymongo.ASCENDING)
             ],
             sparse=True,
             background=True