Ethereum developers and investors are urging caution over Glamsterdam, the network’s next major upgrade, after concerns that new gas pricing rules could disrupt existing smart contracts. Security researchers estimate that roughly 200,000 contracts could be affected, including contracts that hold user funds and cannot be updated. Deployed Ethereum code is immutable by default, so contracts written under the current cost structure cannot be rewritten to absorb the new pricing.

Two developers filed rival proposals on November 8 seeking to prevent Glamsterdam from breaking contracts already in use. Curve Finance founder Michael Egorov warned that the upgrade, in its current form, could trigger an emergency hard fork, meaning a reactive rule change that requires node operators across the network to upgrade in coordination. Ethereum investor Ryan Berckmans also reversed his earlier support for activating Glamsterdam quickly.

At an October 29 meeting, developers tentatively discussed holding a private Glamsterdam test from November 16 to 20 at the earliest. That schedule was discussed before the two new proposals were filed.

Calls for a Pause

Curve Finance founder Michael Egorov issued a direct appeal on X, writing, “Please don’t break the chain.” He warned that Glamsterdam in its current form appeared likely to result in “another emergency hard fork back, with a lot of drama.”

Dear @ethereum – please don't break the chain. It does look like Glamsterdam in the current form would lead to another emergency hard fork back, with a lot of drama. I am sure, it can be made without breaking immutable contracts which hold funds — Michael Egorov (@newmichwill) November 7, 2026

Ethereum investor Ryan Berckmans changed his position after reviewing the risks. He had initially supported moving ahead quickly, arguing that Ethereum could not guarantee unchanged gas prices for every application. He later wrote on X:

“We should (clearly, now) not continue towards Glam activation asap. I was wrong to say so,” Berckmans wrote on X.

We should (clearly, now) not continue towards Glam activation asap. I was wrong to say so. I since learned that the problem is essentially worse than is generally understood (incl by me). We have an urgent need for more people to write more things with data in public on this. — Ryan Berckmans ⟠ (@ryanberckmans) November 7, 2026

Security researcher pcaversaccio said the upgrade should not proceed in its current form. “imho Glamsterdam should not be shipped in its current form, period,” the researcher wrote, adding that the gas increases had been brought to the attention of core developers about two weeks earlier.

Pseudonymous developer banteg said a public analysis had already identified about 200,000 potentially affected contracts. According to banteg, weaknesses in the analysis method could mean that many more contracts were missed, while several high-profile protocols were also exposed.

Gas Changes and Proposed Fixes

The concerns involve two Glamsterdam proposals, EIP-8037 and EIP-8038. Ethereum Improvement Proposals (EIPs) are the formal specifications through which the network defines and adopts rule changes. The proposals would increase the gas charges Ethereum applies to the creation of contracts and access to stored blockchain data.

Gas is the fee used to price each step performed by a smart contract. Under EIP-8037, the base charge for creating a contract would increase from 32,000 gas to 183,600, before code-storage and execution costs are included.

Many applications were built on the assumption that those costs would remain fixed. Some reserve a fixed amount of gas when calling another application, meaning that a price increase could cause those calls to fail—when actual costs exceed the gas a contract has reserved, the call can revert. Security firm ChainSecurity identified eight such assumptions that could break.

Leo Glisic’s proposal, EIP-8488, would divide Ethereum’s instruction set into two versions. Existing contracts would retain the old gas schedule, while new contracts would need to use “V2” opcodes carrying the new pricing.

A separate draft from Giulio Rebuffo proposes using two gas meters in each transaction. One would track execution under the old rules, allowing contracts to see the costs they expect, while the other would determine the actual fee using the new prices.

Rebuffo’s draft says that no execution-client implementation or consensus tests have been run for the design. Neither EIP-8488 nor Rebuffo’s proposal has been approved for Glamsterdam, and neither specifies a target date.

Testing Delayed

Developers postponed the October 26 Glamsterdam activation on the Hoodi test network after the security warnings. Hoodi is one of Ethereum’s public test networks, where upcoming protocol changes are rehearsed before reaching the main network. The delay included the Amsterdam execution-layer changes, the Gloas consensus changes and a plan to increase Hoodi’s gas limit to 200 million.

On November 6, Ethereum Foundation developer Marius van der Wijden said the foundation was working with ChainSecurity and Dedaub to review affected applications. The team is also collecting feedback from developers.

The private test discussed for November 16 to 20 was therefore only tentative and was scheduled before the competing proposals were filed. What remains open is whether either compatibility draft earns a place in Glamsterdam’s scope, and what the ongoing review with ChainSecurity and Dedaub turns up as developer feedback continues to be collected.

Primary source: https://coincentral.com/ethereum-glamsterdam-upgrade-faces-pushback-as-200000-smart-contracts-risk-breaking/