# Child of a Child Workflow

**URL:** https://community.temporal.io/t/child-of-a-child-workflow/8791
**Category:** Community Support
**Tags:** java-sdk, child-workflow
**Created:** [July 10, 2023, 2:39pm UTC](https://community.temporal.io/t/child-of-a-child-workflow/8791 "2023-07-10T14:39:57Z")
**Posts on this page:** 3
**Page:** 1

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### Author: ![Krishnendu\_Kunti](https://sea2.discourse-cdn.com/flex016/user_avatar/community.temporal.io/krishnendu_kunti/32/3891_2.png) [@Krishnendu\_Kunti](https://community.temporal.io/u/Krishnendu_Kunti)
#### Post date: [July 10, 2023, 2:39pm UTC](https://community.temporal.io/t/child-of-a-child-workflow/8791/1 "2023-07-10T14:39:57Z")

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Hi  
I have following scenario:

Parent workflow–\> Child workflow–\> Child of Child workflow

I am calling both Child and Child of Child workflow using child workflow stub

```
    ChildWorkflowOptions childWorkflowOptions =
            ChildWorkflowOptions.newBuilder()
                    .setWorkflowId("childWorkflow-").build();
    ChildofChildWorkflow child = Workflow.newChildWorkflowStub(ChildofChildWorkflow.class, childWorkflowOptions);

```

However, I am getting the **following exception** :

java.lang.Error: Unknown workflow type “ChildofChildWorkflow”. Known types are [ParentWorkflow, ChildWorkflow]

Please let me know its not possible to use childworkflow stub in Child of Child workflow.

Thanks for the help  
Best Regards’  
Krishnendu

---

<div class="post-metadata">

### Author: ![antonio.perez](https://sea2.discourse-cdn.com/flex016/user_avatar/community.temporal.io/antonio.perez/32/2417_2.png) [@antonio.perez](https://community.temporal.io/u/antonio.perez)
#### Post date: [July 10, 2023, 2:58pm UTC](https://community.temporal.io/t/child-of-a-child-workflow/8791/2 "2023-07-10T14:58:50Z")

</div>

Hello @Krishnendu_Kunti

that should be fine,

ensure you register the `ChildofChildWorkflow ` in the worker when you create it

`worker.registerWorkflowImplementationTypes`, it looks like you have only registered `ParentWorkflow, ChildWorkflow`

let me know if it works.

Antonio

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<div class="post-metadata">

### Author: ![Krishnendu\_Kunti](https://sea2.discourse-cdn.com/flex016/user_avatar/community.temporal.io/krishnendu_kunti/32/3891_2.png) [@Krishnendu\_Kunti](https://community.temporal.io/u/Krishnendu_Kunti)
#### Post date: [July 10, 2023, 3:29pm UTC](https://community.temporal.io/t/child-of-a-child-workflow/8791/3 "2023-07-10T15:29:29Z")

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Hi @antonio.perez

Thank you for pointing out.

Best Regards  
Krishnendu