diff --git a/synapse/push/baserules.py b/synapse/push/baserules.py
index b33714f1f..6e333a3d2 100644
--- a/synapse/push/baserules.py
+++ b/synapse/push/baserules.py
@@ -100,7 +100,7 @@ def make_base_override_rules():
                 }
             ],
             'actions': [
-                'dont-notify',
+                'dont_notify',
             ]
         },
         {