diff --git a/synapse/notifier.py b/synapse/notifier.py
index 7eeba6d28e5749c56e5c012f7748147a788ba9a4..f9fcc0ca2580c9fe025e5f5405a9870d58e2388d 100644
--- a/synapse/notifier.py
+++ b/synapse/notifier.py
@@ -550,3 +550,9 @@ class Notifier(object):
                 break
 
         defer.returnValue(result)
+
+    def wait_once_for_replication(self):
+        """Returns a deferred which resolves when there is new data for
+        replication to handle.
+        """
+        return self.replication_deferred.observe()