diff --git a/schema/index.yaml b/schema/index.yaml
index cebd05e..64c756e 100644
--- a/schema/index.yaml
+++ b/schema/index.yaml
@@ -27,6 +27,8 @@ $defs:
     properties:
       id:
         type: string
+      issue:
+        type: number
       type:
         type: string
         enum: