diff --git a/story/utils.py b/story/utils.py
index 95b95e7..51f65ba 100644
--- a/story/utils.py
+++ b/story/utils.py
@@ -95,6 +95,7 @@ def mapping_variation_pairs(mapping):
     mapping_list.append((" " + mapping[0]+".", " " + mapping[1]+"."))
     mapping_list.append((" " + mapping[0]+"?", " " + mapping[1]+"?"))
     mapping_list.append((" " + mapping[0]+"!", " " + mapping[1]+"!"))
+    return mapping_list
 
 
 first_to_second_mappings = [