diff --git a/zipline/utils/test_utils.py b/zipline/utils/test_utils.py
index 5f36396b..e444ff09 100644
--- a/zipline/utils/test_utils.py
+++ b/zipline/utils/test_utils.py
@@ -288,7 +288,7 @@ def make_simple_asset_info(assets, start_date, end_date, symbols=None):
     end_date : pd.Timestamp
     symbols : list, optional
         Symbols to use for the assets.
-        If not provided, symbols are generated from upper-case letters.
+        If not provided, symbols are generated from the sequence 'A', 'B', ...
 
     Returns
     -------