# Optimism proposes Upgrade 16 bridge and guardian changes

> The proposal would update OptimismPortal for future cross-chain messaging, remove DeputyGuardianModule, update DeputyPauseModule, and raise the maximum gas limit from 200 million to 500 million.

- URL: https://riadefi.com/on-chain/2025-06-20-optimism-bridge-superchain-upgrade-16-portal-guardian-pause-proposal/
- Type: Control change
- Stage: Proposed
- Evidence: confirmed
- Materiality: material
- Event date: 2025-06-20
- Version: 1, published 2026-08-22 (first published 2026-08-22)
- Follow-up: 2025-07-03
- Advisor-relevant: yes
- Affects: Optimism canonical bridge (protocol)

## What happened

Optimism published Superchain Upgrade 16 for review and extended its bug-bounty scope to the proposed upgrade calldata before production deployment.

## What changed

The proposal would update OptimismPortal for future cross-chain messaging, remove DeputyGuardianModule, update DeputyPauseModule, and raise the maximum gas limit from 200 million to 500 million.

## What did not change

The notice states that Upgrade 16 does not enable Superchain interoperability, and it does not establish that the proposed payload was approved or executed.

## Confirmed

- Upgrade 16 was the first proposed upgrade covered by the expanded calldata bug bounty.
- The proposed OptimismPortal changes are preparatory and do not turn on interoperability.
- The proposal includes removal of DeputyGuardianModule and updates to DeputyPauseModule.
- The maximum gas limit would increase from 200 million to 500 million.

## Still open

- The final governance outcome and executed payload.
- The deployed guardian and pause-module state after any execution.
- Whether the final code or calldata changes during security review.

## What it means for an advisor

- Review the Optimism bridge memo's upgrade, pause, and guardian control map before treating Upgrade 16 as operative.
- Verify the final governance payload and deployed contract state after execution; the expanded bounty does not establish safety or approval.

## Sources

1. [Optimism Extends $2 Million Bug Bounty Program to Protocol Upgrades Ahead of Superchain Interop](https://optimism.io/blog/optimism-extends-2-million-bug-bounty-program-to-protocol-upgrades-ahead-of-superchain-interop) · Optimism Foundation · 2025-06-20


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Published by Ketju Research on RIADeFi (https://riadefi.com). Educational research for financial professionals; not investment, legal, tax, or compliance advice.