diff --git a/synapse/storage/schema/delta/17/user_threepids.sql b/synapse/storage/schema/delta/17/user_threepids.sql
index f3d1efe4e0..c17715ac80 100644
--- a/synapse/storage/schema/delta/17/user_threepids.sql
+++ b/synapse/storage/schema/delta/17/user_threepids.sql
@@ -4,6 +4,6 @@ CREATE TABLE user_threepids (
     address TEXT NOT NULL,
     validated_at BIGINT NOT NULL,
     added_at BIGINT NOT NULL,
-    CONSTRAINT user_medium_address UNIQUE (user, medium, address)
+    CONSTRAINT user_medium_address UNIQUE (user_id, medium, address)
 );
 CREATE INDEX user_threepids_user_id ON user_threepids(user_id);