diff --git a/threadless_router/backends/httptester/backend.py b/threadless_router/backends/httptester/backend.py
index 4a0fb94..fb31001 100644
--- a/threadless_router/backends/httptester/backend.py
+++ b/threadless_router/backends/httptester/backend.py
@@ -8,6 +8,7 @@ class HttpTesterCacheBackend(BackendBase):
 
     def send(self, msg):
         store_message('out', msg.connection.identity, msg.text)
+        return True
 
     def start(self):
         """ Override BackendBase.start(), which never returns """