diff --git a/requirements.txt b/requirements.txt
index 4b6c15883..a3fbb420e 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -11,4 +11,4 @@ monotonic==0.3
 
 git+https://github.com/alphagov/notifications-python-client.git@1.0.0#egg=notifications-python-client==1.0.0
 
-git+https://github.com/alphagov/notifications-utils.git@5.2.0#egg=notifications-utils==5.2.0
+git+https://github.com/alphagov/notifications-utils.git@5.2.3#egg=notifications-utils==5.2.3