diff --git a/gocardless_pro/services/subscriptions_service.py b/gocardless_pro/services/subscriptions_service.py
index dc487854..3c5092a8 100644
--- a/gocardless_pro/services/subscriptions_service.py
+++ b/gocardless_pro/services/subscriptions_service.py
@@ -158,7 +158,7 @@ def pause(self,identity,params=None, headers=None):
         When `pause_cycles` is omitted the subscription is paused until the
         [resume endpoint](#subscriptions-resume-a-subscription) is called.
         If the subscription is collecting a fixed number of payments,
-        `end_date` will be set to `nil`.
+        `end_date` will be set to `null`.
         When paused indefinitely, `upcoming_payments` will be empty.
         
         When `pause_cycles` is provided the subscription will be paused for the