diff --git a/migrations/000.501.sql b/migrations/000.501.sql
new file mode 100644
index 0000000..90bbf18
--- /dev/null
+++ b/migrations/000.501.sql
@@ -0,0 +1,23 @@
+ALTER TABLE discount_codes
+  ADD COLUMN IF NOT EXISTS applicable_on_sales BOOLEAN NOT NULL DEFAULT FALSE;
+
+UPDATE discount_codes
+   SET applicable_on_sales = TRUE
+ WHERE type != '%';
+
+CREATE OR REPLACE FUNCTION discount_code_applicable_on_sales()
+  RETURNS TRIGGER AS $$
+    BEGIN
+        IF NEW.type != '%' THEN
+            NEW.applicable_on_sales := TRUE;
+        END IF;
+        RETURN NEW;
+    END;
+$$ LANGUAGE plpgsql;
+
+DROP TRIGGER IF EXISTS discount_code_applicable_on_sales ON discount_codes;
+
+CREATE TRIGGER discount_code_applicable_on_sales
+  BEFORE INSERT OR UPDATE ON discount_codes
+  FOR EACH ROW
+  EXECUTE FUNCTION discount_code_applicable_on_sales();