diff --git a/schema/types/forms/definitions.yml b/schema/types/forms/definitions.yml
index 996c6a7..63bffda 100644
--- a/schema/types/forms/definitions.yml
+++ b/schema/types/forms/definitions.yml
@@ -30,6 +30,8 @@ definitions:
     description: 質問の配列
     type: object
     properties:
+      form_id:
+        $ref: "./components.yml#/components/schemas/id"
       questions:
         $ref: "./components.yml#/components/schemas/questions"
   question_id: