# zkSync contracts v9 upgrade announcement
We will start the notice period to upgrade zkSync contracts to a new version today.
The exact changes in the code of the contracts can be found here (opens new window).
nonReentrantmodifier for all external functions as additional protection from reentrancy attack.
- New method for EIP-712
- A check for non-zero address when changing the governor.
WithdrawalPendingevent parameters changed.
Withdrawalevent parameters changed.
memoryfor gas cost optimization.
- The visibility of the function
authFactsResetTimerchanged from internal to public.
proveBlocksignores already proven blocks.
- Withdrawals are no longer finalized in the