diff --git a/synapse/storage/room.py b/synapse/storage/room.py
index 23688430b..d91c85307 100644
--- a/synapse/storage/room.py
+++ b/synapse/storage/room.py
@@ -589,7 +589,7 @@ class RoomStore(SQLBaseStore):
                     """
                         UPDATE remote_media_cache
                         SET quarantined_by = ?
-                        WHERE media_origin AND media_id = ?
+                        WHERE media_origin = ? AND media_id = ?
                     """,
                     (
                         (quarantined_by, origin, media_id)