diff --git a/synapse/storage/schema/delta/51/monthly_active_users.sql b/synapse/storage/schema/delta/51/monthly_active_users.sql
index b3c0e1a67..f2b6d3e31 100644
--- a/synapse/storage/schema/delta/51/monthly_active_users.sql
+++ b/synapse/storage/schema/delta/51/monthly_active_users.sql
@@ -13,7 +13,7 @@
  * limitations under the License.
  */
 
--- a table of users who have requested that their details be erased
+-- a table of monthly active users, for use where blocking based on mau limits
 CREATE TABLE monthly_active_users (
     user_id TEXT NOT NULL,
     timestamp BIGINT NOT NULL