diff --git a/spec/definitions/InvoiceUrlParams.yaml b/spec/definitions/InvoiceUrlParams.yaml
index 10eae19cc9..28e1621640 100644
--- a/spec/definitions/InvoiceUrlParams.yaml
+++ b/spec/definitions/InvoiceUrlParams.yaml
@@ -1,6 +1,5 @@
 type: object
 description: Set of key-value pairs to be included in generated invoice URL
-required: []
 additionalProperties: true
 properties:
   email: