# Deregistering a custom Hook from the CloudFormation registry
<a name="deregistering-hooks"></a>

Deregistering a custom Hook marks the extension or extension version as `DEPRECATED` in the CloudFormation registry, which removes it from active use. Once deprecated, the custom Hook can't be used in a CloudFormation operation.

**Note**  
Before deregistering the Hook, you must individually deregister all previous active versions of that extension. For more information, see [https://docs.amazonaws.cn/AWSCloudFormation/latest/APIReference/API_DeregisterType.html](https://docs.amazonaws.cn/AWSCloudFormation/latest/APIReference/API_DeregisterType.html).

To deregister a Hook, use the [https://docs.amazonaws.cn/cli/latest/reference/cloudformation/deregister-type.html](https://docs.amazonaws.cn/cli/latest/reference/cloudformation/deregister-type.html) operation and specify your Hook ARN.

```
$ aws cloudformation deregister-type \
    --arn HOOK_TYPE_ARN
```

This command doesn't produce an output.