diff --git a/product_contract/migrations/12.0.3.0.0/pre-migration.py b/product_contract/migrations/12.0.3.0.0/pre-migration.py
new file mode 100644
index 00000000..31b3f179
--- /dev/null
+++ b/product_contract/migrations/12.0.3.0.0/pre-migration.py
@@ -0,0 +1,10 @@
+def migrate(cr, version):
+    # pre-paid/post-paid becomes significant for monthlylastday too,
+    # make sure it has the value that was implied for previous versions.
+    cr.execute(
+        """\
+            UPDATE product_template
+            SET recurring_invoicing_type = 'post-paid'
+            WHERE recurring_rule_type = 'monthlylastday'
+        """
+    )