diff --git a/backend/src/database/migrations/004_create_einsaetze.sql b/backend/src/database/migrations/004_create_einsaetze.sql
index 29c40e4..3e9daa1 100644
--- a/backend/src/database/migrations/004_create_einsaetze.sql
+++ b/backend/src/database/migrations/004_create_einsaetze.sql
@@ -103,8 +103,9 @@ CREATE INDEX IF NOT EXISTS idx_einsaetze_alarm_time      ON einsaetze(alarm_time
 CREATE INDEX IF NOT EXISTS idx_einsaetze_einsatz_art     ON einsaetze(einsatz_art);
 CREATE INDEX IF NOT EXISTS idx_einsaetze_status          ON einsaetze(status);
 CREATE INDEX IF NOT EXISTS idx_einsaetze_einsatzleiter   ON einsaetze(einsatzleiter_id);
-CREATE INDEX IF NOT EXISTS idx_einsaetze_alarm_year      ON einsaetze(EXTRACT(YEAR FROM alarm_time));
-CREATE INDEX IF NOT EXISTS idx_einsaetze_alarm_art_year  ON einsaetze(einsatz_art, EXTRACT(YEAR FROM alarm_time));
+-- Note: EXTRACT(YEAR FROM timestamptz) is STABLE (timezone-dependent), not IMMUTABLE,
+-- so it cannot be used in expression indexes. Use alarm_time range scans for year filtering.
+CREATE INDEX IF NOT EXISTS idx_einsaetze_alarm_art       ON einsaetze(einsatz_art, alarm_time DESC);
 
 -- Auto-update updated_at
 CREATE TRIGGER update_einsaetze_updated_at