diff --git a/requirements.txt b/requirements.txt
index 672bdd706..00416dcc8 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -25,6 +25,6 @@ docopt==0.6.2
 # pin to minor version 3.1.x
 notifications-python-client>=3.1,<3.2
 
-git+https://github.com/alphagov/notifications-utils.git@13.2.0#egg=notifications-utils==13.2.0
+git+https://github.com/alphagov/notifications-utils.git@13.5.0#egg=notifications-utils==13.5.0
 
 git+https://github.com/alphagov/boto.git@2.43.0-patch3#egg=boto==2.43.0-patch3