diff --git a/CHANGELOG.md b/CHANGELOG.md
index dc837e95..9886bd69 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -156,6 +156,7 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 - Fixed `geo_bounding_box` and `geo_shape` queries ([#531](https://github.com/opensearch-project/opensearch-api-specification/pull/531))
 - Fixed tasks namespace schemas ([#520](https://github.com/opensearch-project/opensearch-api-specification/pull/520))
 - Fixed `/_plugins/_transform/_preview` ([#568](https://github.com/opensearch-project/opensearch-api-specification/pull/568))
+- Fixed create/delete/index operation in `_bulk` ([#582](https://github.com/opensearch-project/opensearch-api-specification/pull/582))
 
 ### Security
 
diff --git a/spec/schemas/_core.bulk.yaml b/spec/schemas/_core.bulk.yaml
index 9006cfe2..417d1ffd 100644
--- a/spec/schemas/_core.bulk.yaml
+++ b/spec/schemas/_core.bulk.yaml
@@ -20,9 +20,7 @@ components:
       minProperties: 1
       maxProperties: 1
     IndexOperation:
-      allOf:
-        - $ref: '#/components/schemas/WriteOperation'
-        - type: object
+      $ref: '#/components/schemas/WriteOperation'
     WriteOperation:
       allOf:
         - $ref: '#/components/schemas/OperationBase'
@@ -64,9 +62,7 @@ components:
         version_type:
           $ref: '_common.yaml#/components/schemas/VersionType'
     CreateOperation:
-      allOf:
-        - $ref: '#/components/schemas/WriteOperation'
-        - type: object
+      $ref: '#/components/schemas/WriteOperation'
     UpdateOperation:
       allOf:
         - $ref: '#/components/schemas/OperationBase'
@@ -78,9 +74,7 @@ components:
             retry_on_conflict:
               type: number
     DeleteOperation:
-      allOf:
-        - $ref: '#/components/schemas/OperationBase'
-        - type: object
+      $ref: '#/components/schemas/OperationBase'
     UpdateAction:
       type: object
       properties: