diff --git a/backend/src/main/resources/db/migration/V77__add_timeline_events.sql b/backend/src/main/resources/db/migration/V77__add_timeline_events.sql
index aba99c10..b83745e2 100644
--- a/backend/src/main/resources/db/migration/V77__add_timeline_events.sql
+++ b/backend/src/main/resources/db/migration/V77__add_timeline_events.sql
@@ -56,10 +56,9 @@ CREATE TABLE timeline_event_documents (
 );
 
 -- Indexes added up-front (avoid the V62 FK-index retrofit debt): the two query columns plus
--- explicit indexes on all four FK columns.
+-- the inverse-side FK columns. timeline_event_id needs no extra index on either join table —
+-- it is the leading column of the composite PK, so the PK index already serves those lookups.
 CREATE INDEX idx_timeline_events_event_date ON timeline_events (event_date);
 CREATE INDEX idx_timeline_events_type ON timeline_events (type);
 CREATE INDEX idx_timeline_event_persons_person_id ON timeline_event_persons (person_id);
-CREATE INDEX idx_timeline_event_persons_event_id ON timeline_event_persons (timeline_event_id);
 CREATE INDEX idx_timeline_event_documents_document_id ON timeline_event_documents (document_id);
-CREATE INDEX idx_timeline_event_documents_event_id ON timeline_event_documents (timeline_event_id);