diff --git a/migrations/000.141.sql b/migrations/000.141.sql
new file mode 100644
index 0000000..5c4b720
--- /dev/null
+++ b/migrations/000.141.sql
@@ -0,0 +1,12 @@
+-- P5-4494: remove all contract customer discounts except general discount
+
+ALTER TABLE contract_customers
+    ADD COLUMN discount INTEGER DEFAULT 0;
+
+UPDATE contract_customers SET discount = (
+    SELECT discount FROM contract_customers_discounts
+    WHERE contractcustomerid = contract_customers.contractcustomerid
+    AND productgroupid IS NULL AND materialid IS NULL
+);
+
+DROP TABLE contract_customers_discounts;