diff --git a/synapse/crypto/keyring.py b/synapse/crypto/keyring.py
index 105de2b58..22bb325cf 100644
--- a/synapse/crypto/keyring.py
+++ b/synapse/crypto/keyring.py
@@ -57,7 +57,8 @@ Attributes:
     json_object(dict): The JSON object to verify.
     deferred(twisted.internet.defer.Deferred):
         A deferred (server_name, key_id, verify_key) tuple that resolves when
-        a verify key has been fetched
+        a verify key has been fetched. The deferreds' callbacks are run with no
+        logcontext.
 """
 
 
@@ -284,19 +285,21 @@ class Keyring(object):
                     if not missing_keys:
                         break
 
-                for verify_request in requests_missing_keys.values():
-                    verify_request.deferred.errback(SynapseError(
-                        401,
-                        "No key for %s with id %s" % (
-                            verify_request.server_name, verify_request.key_ids,
-                        ),
-                        Codes.UNAUTHORIZED,
-                    ))
+                with PreserveLoggingContext():
+                    for verify_request in requests_missing_keys.values():
+                        verify_request.deferred.errback(SynapseError(
+                            401,
+                            "No key for %s with id %s" % (
+                                verify_request.server_name, verify_request.key_ids,
+                            ),
+                            Codes.UNAUTHORIZED,
+                        ))
 
         def on_err(err):
-            for verify_request in verify_requests:
-                if not verify_request.deferred.called:
-                    verify_request.deferred.errback(err)
+            with PreserveLoggingContext():
+                for verify_request in verify_requests:
+                    if not verify_request.deferred.called:
+                        verify_request.deferred.errback(err)
 
         do_iterations().addErrback(on_err)
 
@@ -714,7 +717,8 @@ class Keyring(object):
 def _handle_key_deferred(verify_request):
     server_name = verify_request.server_name
     try:
-        _, key_id, verify_key = yield verify_request.deferred
+        with PreserveLoggingContext():
+            _, key_id, verify_key = yield verify_request.deferred
     except IOError as e:
         logger.warn(
             "Got IOError when downloading keys for %s: %s %s",