diff --git a/synapse/util/__init__.py b/synapse/util/__init__.py
index 9ad613b8f1..e57fb0e914 100644
--- a/synapse/util/__init__.py
+++ b/synapse/util/__init__.py
@@ -38,7 +38,7 @@ class Clock(object):
     def call_later(self, delay, callback):
         current_context = LoggingContext.current_context()
         def wrapped_callback():
-            current_context.thread_local.current_context = current_context
+            LoggingContext.thread_local.current_context = current_context
             callback()
         return reactor.callLater(delay, wrapped_callback)