diff --git a/changelog.d/3980.bugfix b/changelog.d/3980.bugfix
new file mode 100644
index 000000000000..7578414ede72
--- /dev/null
+++ b/changelog.d/3980.bugfix
@@ -0,0 +1 @@
+Fix some instances of ExpiringCache not expiring cache items
diff --git a/synapse/app/homeserver.py b/synapse/app/homeserver.py
index a98fdbd210ef..e3f0d99a3ff2 100755
--- a/synapse/app/homeserver.py
+++ b/synapse/app/homeserver.py
@@ -386,7 +386,6 @@ def start():
         hs.get_pusherpool().start()
         hs.get_datastore().start_profiling()
         hs.get_datastore().start_doing_background_updates()
-        hs.get_federation_client().start_get_pdu_cache()
 
     reactor.callWhenRunning(start)