diff --git a/gratipay/utils/fake_data.py b/gratipay/utils/fake_data.py
index 075c7c52ec..045520a17e 100644
--- a/gratipay/utils/fake_data.py
+++ b/gratipay/utils/fake_data.py
@@ -220,6 +220,8 @@ def fake_payment(db, participant, team, timestamp, amount, payday, direction):
 
 
 def fake_exchange(db, participant, amount, fee, timestamp):
+    """Create a fake exchange for a participant
+    """
     route=get_exchange_route(db, participant.id)
     ref = '%s-%s-%s' % (participant.username, route, timestamp.microsecond)
     return insert_fake_data( db