diff --git a/changelog.d/5645.misc b/changelog.d/5645.misc
new file mode 100644
index 000000000..4fa9699e4
--- /dev/null
+++ b/changelog.d/5645.misc
@@ -0,0 +1 @@
+Remove unused and unnecessary check for FederationDeniedError in _exception_to_failure.
\ No newline at end of file
diff --git a/synapse/handlers/e2e_keys.py b/synapse/handlers/e2e_keys.py
index 55b4ab3a1..fdfe8611b 100644
--- a/synapse/handlers/e2e_keys.py
+++ b/synapse/handlers/e2e_keys.py
@@ -22,7 +22,7 @@ from canonicaljson import encode_canonical_json, json
 
 from twisted.internet import defer
 
-from synapse.api.errors import CodeMessageException, FederationDeniedError, SynapseError
+from synapse.api.errors import CodeMessageException, SynapseError
 from synapse.logging.context import make_deferred_yieldable, run_in_background
 from synapse.types import UserID, get_domain_from_id
 from synapse.util.retryutils import NotRetryingDestination
@@ -350,9 +350,6 @@ def _exception_to_failure(e):
     if isinstance(e, NotRetryingDestination):
         return {"status": 503, "message": "Not ready for retry"}
 
-    if isinstance(e, FederationDeniedError):
-        return {"status": 403, "message": "Federation Denied"}
-
     # include ConnectionRefused and other errors
     #
     # Note that some Exceptions (notably twisted's ResponseFailed etc) don't