diff --git a/synapse/handlers/_base.py b/synapse/handlers/_base.py
index 95bb06395..5fd20285d 100644
--- a/synapse/handlers/_base.py
+++ b/synapse/handlers/_base.py
@@ -93,7 +93,7 @@ class BaseHandler(object):
             membership_event = state.get((EventTypes.Member, user_id), None)
             if membership_event:
                 was_forgotten_at_event = yield self.store.was_forgotten_at(
-                    membership_event.user_id,
+                    membership_event.state_key,
                     membership_event.room_id,
                     membership_event.event_id
                 )
diff --git a/synapse/storage/roommember.py b/synapse/storage/roommember.py
index 5e92cdc81..c3e11b91d 100644
--- a/synapse/storage/roommember.py
+++ b/synapse/storage/roommember.py
@@ -295,7 +295,7 @@ class RoomMemberStore(SQLBaseStore):
             sql = (
                 "SELECT"
                 "  COUNT(*)"
-                "FROM"
+                " FROM"
                 "  room_memberships"
                 " WHERE"
                 "  user_id = ?"
@@ -318,8 +318,8 @@ class RoomMemberStore(SQLBaseStore):
         def f(txn):
             sql = (
                 "SELECT"
-                "  COUNT(*)"
-                "FROM"
+                "  forgotten"
+                " FROM"
                 "  room_memberships"
                 " WHERE"
                 "  user_id = ?"
@@ -327,11 +327,9 @@ class RoomMemberStore(SQLBaseStore):
                 "  room_id = ?"
                 " AND"
                 "  event_id = ?"
-                " AND"
-                "  forgotten = 1"
             )
             txn.execute(sql, (user_id, room_id, event_id))
             rows = txn.fetchall()
             return rows[0][0]
-        count = yield self.runInteraction("did_forget_membership_at", f)
-        defer.returnValue(count == 1)
+        forgot = yield self.runInteraction("did_forget_membership_at", f)
+        defer.returnValue(forgot == 1)