diff --git a/synapse/storage/databases/main/roommember.py b/synapse/storage/databases/main/roommember.py
index b80ddcd3baa..3fde7d23205 100644
--- a/synapse/storage/databases/main/roommember.py
+++ b/synapse/storage/databases/main/roommember.py
@@ -1617,7 +1617,7 @@ async def set_room_participation(self, room_id: str, user_id: str) -> None:
         await self.db_pool.simple_update(
             "room_memberships",
             {"user_id": user_id, "room_id": room_id},
-            {"participant": True},
+            {"participant": 1},
             "update_room_participation",
         )
 
@@ -1713,7 +1713,7 @@ def _background_populate_participant_per_room_txn(
                     txn,
                     table="room_memberships",
                     keyvalues={"user_id": participant},
-                    updatevalues={"participant": True},
+                    updatevalues={"participant": 1},
                 )
 
         current_room_id = await self.db_pool.runInteraction(