diff --git a/lib/core/form/components/widgets/core/form.model.ts b/lib/core/form/components/widgets/core/form.model.ts
index f4396b0fe8..573acd5b87 100644
--- a/lib/core/form/components/widgets/core/form.model.ts
+++ b/lib/core/form/components/widgets/core/form.model.ts
@@ -48,6 +48,7 @@ export interface FormRepresentationModel {
     tabs?: any[];
     outcomes?: any[];
     formDefinition?: {
+        [key: string]: any;
         fields?: any[];
     };
 }