diff --git a/scripts/hist_importer.py b/scripts/hist_importer.py
index 1b7bbde53..84fada560 100755
--- a/scripts/hist_importer.py
+++ b/scripts/hist_importer.py
@@ -31,6 +31,8 @@ import os
 
 class Error(Exception):
 
+    """Exception for errors in this module."""
+
     pass