# Update Chain Specs in Polkadot Vault

In most cases, chain specs need to be scanned only when adding a new chain. However, you need to update them if the chain updates its address format, native token, or even genesis hash.

Your **Polkadot Vault Device** is always offline and is air-gapped, so specs are updated via scanning a QR code. You can use the [Nova Wallet Metadata Portal](https://metadata.novasama.io/) to find QR codes which will provide your **Polkadot Vault Device** with the information required to update the chain specs.

{% hint style="warning" %}
The following steps need to be carried out on your **Polkadot Vault Device**.
{% endhint %}

1. Navigate to the  [Novasama Technologies Metadata Portal](https://metadata.novasama.io/#/polkadot). Note: this should be done on a device which is **not** your Polkadot Vault device.
2. On the metadata portal, `select` the **blockchain** that you wish to update the metadata for.
3. `Select` the **Chain Specs** tab at the top of the metadata portal screen.
4. Using your Polkadot Vault device, `select` the **QR code scanner**.
5. Scan the **Chain specs QR code** with your Polkadot Vault device.
6. Review the verifier certificate and then `select` **Approve** at the bottom of the screen on your Polkadot Vault device.
7. If there was a metadata update as well, follow these steps next: [Update Chain Metadata in Polkadot Vault](/nova-wallet-wiki/wallet-management/hardware-wallets/polkadot-vault/update-chain-metadata-in-polkadot-vault.md).


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