diff --git a/db/README.md b/db/README.md
index 77729ed..b828dc6 100644
--- a/db/README.md
+++ b/db/README.md
@@ -19,6 +19,7 @@
 15. `db/migrations/0019_allow_multiple_open_stock_lots.sql`
 16. `db/migrations/0020_include_stock_adjustments_in_balance.sql`
 17. `db/migrations/0021_stock_lot_activation_selection.sql`
+18. `db/migrations/0022_backfill_stock_lot_activation_selection.sql`
 
 ## Beispielausfuehrung
 
diff --git a/db/migrations/0022_backfill_stock_lot_activation_selection.sql b/db/migrations/0022_backfill_stock_lot_activation_selection.sql
new file mode 100644
index 0000000..32349d3
--- /dev/null
+++ b/db/migrations/0022_backfill_stock_lot_activation_selection.sql
@@ -0,0 +1,25 @@
+BEGIN;
+
+WITH qualified AS (
+  SELECT
+    sl.id,
+    sl.product_id,
+    COUNT(*) OVER (PARTITION BY sl.product_id) AS qualified_count
+  FROM stock_lot sl
+  INNER JOIN v_stock_lot_balance v ON v.stock_lot_id = sl.id
+  WHERE sl.status = 'open'
+    AND NULLIF(TRIM(sl.lot_number), '') IS NOT NULL
+    AND sl.manufacturer_party_id IS NOT NULL
+    AND NULLIF(TRIM(sl.manufacturer_lot_number), '') IS NOT NULL
+    AND sl.mfg_date IS NOT NULL
+    AND sl.expiry_date IS NOT NULL
+    AND sl.purchase_date IS NOT NULL
+    AND v.qty_net > 0
+)
+UPDATE stock_lot sl
+SET next_active = TRUE, updated_at = NOW()
+FROM qualified q
+WHERE sl.id = q.id
+  AND q.qualified_count = 1;
+
+COMMIT;