diff --git a/synapse/storage/schema/delta/48/groups_joinable.sql b/synapse/storage/schema/delta/48/groups_joinable.sql
index fb9c7a8d1..39c8fed46 100644
--- a/synapse/storage/schema/delta/48/groups_joinable.sql
+++ b/synapse/storage/schema/delta/48/groups_joinable.sql
@@ -13,4 +13,4 @@
  * limitations under the License.
  */
 
-ALTER TABLE groups ADD COLUMN is_joinable BOOLEAN NOT NULL DEFAULT 0;
+ALTER TABLE groups ADD COLUMN is_joinable BOOLEAN NOT NULL DEFAULT (CAST(0 AS BOOLEAN));