diff --git a/synapse/handlers/message.py b/synapse/handlers/message.py
index 5585ee85cfd0366bc8509dd480e8bd2b7b496640..24c9ffdb201504f2ab48c1835ac73a299f4f1378 100644
--- a/synapse/handlers/message.py
+++ b/synapse/handlers/message.py
@@ -502,7 +502,7 @@ class MessageHandler(BaseHandler):
         # Ensure that we can round trip before trying to persist in db
         try:
             dump = ujson.dumps(event.content)
-            load = ujson.loads(dump)
+            ujson.loads(dump)
         except:
             logger.exception("Failed to encode content: %r", event.content)
             raise