Ethereum Developers Warn Glamsterdam Upgrade Could Break Chain

Why Developers Want to Pause EthereumETH-0.09% Glamsterdam

Ethereum is preparing for one of its major upgrades in 2026, known as Glamsterdam. However, several prominent developers are now urging core engineers to halt the upgrade in its current form.

They warn that the proposed fee changes could accidentally break active smart contracts. If that happens, user funds locked inside those contracts might become permanently stuck.

Please don’t break the chain. It looks like the Glamsterdam upgrade would lead to another emergency hard fork back, with a lot of drama.

That direct warning came from the founder of Curve Finance, a major decentralized finance platform. The concern has quickly sparked intense debate across the entire Ethereum developer community.

Understanding the Problem: Gas Fees and Immutable Code

To understand why developers are worried, we need to look at how Ethereum processes transactions. Every action on the network requires transaction fees, which are calculated in gas units.

At the center of the dispute is EIP-8037. This proposal raises the gas cost for creating new state data, such as storage entries and deploying new smart contracts.

Increasing costs sounds simple enough on the surface. However, many existing smart contracts were written with hardcoded gas limits or check remaining gas during transaction execution.

Once gas prices rise, those automated calls could run out of gas and fail mid-operation. Because deployed smart contracts are immutable, developers cannot simply patch existing code to fix the issue.

Developers Push Back Against EIP-8037

The pushback against EIP-8037 has been swift and vocal. Prominent DeFi developer banteg called the plan completely ridiculous in a social media post on November 7, 2026.

this is completely ridiculous besides the already huge list of 200,000 affected contracts in ethereum/repricing-impact, i found multiple methodological issues that make it miss many more. it affects deployment and operation of several high profile protocols, not just some…

Another developer noted that their team found the same issues before Glamsterdam went live on the Sepolia testnet, which were later confirmed by a security firm.

Rushing out Glamsterdam now disregarding the community feedback would be a mistake.

An Ethereum Foundation board member and security researcher also voiced opposition. They stated they would not push for a network fork that breaks security rules discovered only two weeks prior.

Previous Roadblocks for the 2026 Upgrade

Glamsterdam is designed as one of two major upgrades planned for Ethereum in 2026. However, this is not the first obstacle the upgrade has encountered during testing.

In October, core developers delayed a Glamsterdam test on the Hoodi testnet. That decision was made after security researchers flagged potential operational risks.

Community Advocates Reverse Support

The pushback has even changed the minds of initial Glamsterdam supporters. Influential Ethereum community advocate Ryan Berckmans initially advocated for activating the upgrade as soon as possible.

His initial view was that Ethereum guarantees access to the network, but not specific gas prices. However, hours later on November 7, 2026, Berckmans reversed his stance entirely.

We should (clearly, now) not continue towards Glam activation asap. I was wrong to say so.

Berckmans added that the issue is essentially worse than generally understood. He admitted that the community experienced a collective failure regarding design, due diligence, and public communication.

The bad news on Glam's gas opcode repricing debacle is that we collectively fucked up the design, adequate diligence, and sufficient public communication for us to sooner come to correct consensus on the issue. The good news imo is that we have learned a lot over the years about…

He emphasized that gas introspection—how contracts check remaining gas—is a serious technical issue requiring immediate remediation and more public transparency.

What Lies Ahead for Ethereum

Core developers now face pressure to publish more technical data before Glamsterdam reaches the Ethereum mainnet.

This debate occurs as Ethereum spot ETFs recorded their worst month for net flows since launch — highlighting how institutional flows can shift rapidly during changing market conditions.

Meanwhile, Ethereum co-founder Vitalik Buterin has stated that the subsequent upgrade, Hegota, will be Ethereum's last normal hard fork.

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