diff --git a/sql/branch.sql b/sql/branch.sql
new file mode 100644
index 0000000000..edff038b0a
--- /dev/null
+++ b/sql/branch.sql
@@ -0,0 +1,9 @@
+ALTER TABLE emails DROP CONSTRAINT emails_participant_fkey;
+
+ALTER TABLE emails ALTER COLUMN participant TYPE bigint USING participant::bigint;
+
+CREATE SEQUENCE emails_participant_seq;
+ALTER TABLE emails ALTER COLUMN participant SET DEFAULT nextval('emails_participant_seq');
+ALTER SEQUENCE emails_participant_seq OWNED BY emails.participant;
+
+ALTER TABLE emails ADD FOREIGN KEY (participant) REFERENCES participants(id) ON UPDATE CASCADE ON DELETE RESTRICT;