In November we released a blog post describing the canonical WETH token, a shared implementation of an ERC20 compatible Ether token to be used by a variety of Ethereum dApps. Since establishing the initial version of WETH, a handful of teams identified two improvements that could be made to ease dApp integration and more closely adhere to the ERC20 specification. After some discussion with other Ethereum projects and dApps, the decision to migrate to the improved version of the WETH token seemed logical. Changes included in the new WETH deployed by the Makerdao team are as follows:

The deposit and withdraw functions now log Deposit and Withdrawal events. This makes it easier for dApp developers to track WETH balance changes.

and functions now log and events. This makes it easier for dApp developers to track WETH balance changes. Failed transfers will now revert the transaction rather than returning false , as per the officially accepted ERC20 specification.

Deployed contract addresses

Mainnet : 0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2

: 0xc02aaa39b223fe8d0a0e5c4f27ead9083c756cc2 Kovan : 0xd0a1e359811322d97991e03f863a0c30c2cf029c

: 0xd0a1e359811322d97991e03f863a0c30c2cf029c Ropsten : 0xc778417e063141139fce010982780140aa0cd5ab

: 0xc778417e063141139fce010982780140aa0cd5ab Rinkeby: 0xc778417e063141139fce010982780140aa0cd5ab

How can I migrate my deprecated WETH to the new version?

Head over to the new WETH tab on 0x Portal and you’ll be able to easily unwrap any deprecated WETH tokens and convert your Ether into the newest version of WETH. This functionality will never be removed.

Join the conversation

If you would like to join us in supporting the canonical WETH token within your dApp, feel free to voice your support. We also welcome and appreciate constructive feedback; source code may be found here.