diff --git a/changelog.d/12187.misc b/changelog.d/12187.misc
new file mode 100644
index 000000000000..c53e68faa508
--- /dev/null
+++ b/changelog.d/12187.misc
@@ -0,0 +1 @@
+Remove unused variables.
diff --git a/synapse/storage/databases/main/roommember.py b/synapse/storage/databases/main/roommember.py
index e48ec5f495af..bef675b8453c 100644
--- a/synapse/storage/databases/main/roommember.py
+++ b/synapse/storage/databases/main/roommember.py
@@ -46,7 +46,7 @@
     ProfileInfo,
     RoomsForUser,
 )
-from synapse.types import PersistedEventPosition, StateMap, get_domain_from_id
+from synapse.types import PersistedEventPosition, get_domain_from_id
 from synapse.util.async_helpers import Linearizer
 from synapse.util.caches import intern_string
 from synapse.util.caches.descriptors import _CacheContext, cached, cachedList
@@ -273,7 +273,7 @@ def _get_room_summary_txn(txn):
             txn.execute(sql, (room_id,))
             res = {}
             for count, membership in txn:
-                summary = res.setdefault(membership, MemberSummary([], count))
+                res.setdefault(membership, MemberSummary([], count))
 
             # we order by membership and then fairly arbitrarily by event_id so
             # heroes are consistent
@@ -839,18 +839,14 @@ async def get_joined_hosts(self, room_id: str, state_entry):
 
         with Measure(self._clock, "get_joined_hosts"):
             return await self._get_joined_hosts(
-                room_id, state_group, state_entry.state, state_entry=state_entry
+                room_id, state_group, state_entry=state_entry
             )
 
     @cached(num_args=2, max_entries=10000, iterable=True)
     async def _get_joined_hosts(
-        self,
-        room_id: str,
-        state_group: int,
-        current_state_ids: StateMap[str],
-        state_entry: "_StateCacheEntry",
+        self, room_id: str, state_group: int, state_entry: "_StateCacheEntry"
     ) -> FrozenSet[str]:
-        # We don't use `state_group`, its there so that we can cache based on
+        # We don't use `state_group`, it's there so that we can cache based on
         # it. However, its important that its never None, since two
         # current_state's with a state_group of None are likely to be different.
         #