diff --git a/synapse/config/server.py b/synapse/config/server.py
index 9332e4acd7..086937044f 100644
--- a/synapse/config/server.py
+++ b/synapse/config/server.py
@@ -74,7 +74,7 @@ class ServerConfig(Config):
             return syutil.crypto.signing_key.read_signing_keys(
                 signing_keys.splitlines(True)
             )
-        except Exception as e:
+        except Exception:
             raise ConfigError(
                 "Error reading signing_key."
                 " Try running again with --generate-config"
diff --git a/synapse/crypto/keyclient.py b/synapse/crypto/keyclient.py
index 5949ea0573..7cfec5148e 100644
--- a/synapse/crypto/keyclient.py
+++ b/synapse/crypto/keyclient.py
@@ -17,7 +17,6 @@
 from twisted.web.http import HTTPClient
 from twisted.internet.protocol import Factory
 from twisted.internet import defer, reactor
-from twisted.internet.endpoints import connectProtocol
 from synapse.http.endpoint import matrix_endpoint
 import json
 import logging
diff --git a/synapse/rest/room.py b/synapse/rest/room.py
index a01dab1b8e..c72bdc2c34 100644
--- a/synapse/rest/room.py
+++ b/synapse/rest/room.py
@@ -344,7 +344,7 @@ class RoomInitialSyncRestServlet(RestServlet):
 
     @defer.inlineCallbacks
     def on_GET(self, request, room_id):
-        user = yield self.auth.get_user_by_req(request)
+        yield self.auth.get_user_by_req(request)
         # TODO: Get all the initial sync data for this room and return in the
         # same format as initial sync, that is:
         # {
diff --git a/synapse/storage/keys.py b/synapse/storage/keys.py
index 8189e071a3..4feb8335ba 100644
--- a/synapse/storage/keys.py
+++ b/synapse/storage/keys.py
@@ -104,7 +104,6 @@ class KeyStore(SQLBaseStore):
             ts_now_ms (int): The time now in milliseconds
             verification_key (VerifyKey): The NACL verify key.
         """
-        verify_key_bytes = verify_key.encode()
         return self._simple_insert(
             table="server_signature_keys",
             values={