diff --git a/cms/djangoapps/contentstore/asset_storage_handlers.py b/cms/djangoapps/contentstore/asset_storage_handlers.py
index 1e4dbd61240b..3f77a934f946 100644
--- a/cms/djangoapps/contentstore/asset_storage_handlers.py
+++ b/cms/djangoapps/contentstore/asset_storage_handlers.py
@@ -435,11 +435,15 @@ def _get_assets_in_json_format(assets, course_key, assets_usage_locations_map):
     for asset in assets:
         asset_key = asset['asset_key']
         asset_key_string = str(asset_key)
-        usage_locations = getattr(assets_usage_locations_map, 'asset_key_string', [])
         thumbnail_asset_key = _get_thumbnail_asset_key(asset, course_key)
         asset_is_locked = asset.get('locked', False)
         asset_file_size = asset.get('length', None)
 
+        try:
+            usage_locations = assets_usage_locations_map[asset_key_string]
+        except KeyError:
+            usage_locations = []
+
         asset_in_json = get_asset_json(
             asset['displayname'],
             asset['contentType'],