Ethereum developers have delayed the Glamsterdam upgrade on the Hoodi testnet after auditing firm ChainSecurity warned that proposed gas-accounting changes could break assumptions in existing smart contracts; the Ethereum Foundation has since catalogued eight such invariants.
Two developers submitted competing proposals on 8 November to protect older contracts, but neither has been approved for inclusion in the upgrade.
What Glamsterdam Changes and Why It Matters
The dispute centres on two of the EIPs scheduled for the upgrade. EIP-8037 raises the base gas charge for creating a smart contract from 32,000 to 183,600, excluding additional execution and code storage costs.
EIP-8038 adjusts charges for accessing existing blockchain state, covering operations including SLOAD, SSTORE and cold account access. Some contracts rely on fixed gas costs or on specific behaviour when transactions fail.
Pseudonymous developer banteg cited an analysis estimating roughly 200,000 potentially affected contracts, though methodological issues could mean the true figure is higher.
The Hoodi testnet activation was postponed on 22 October, four days before its scheduled 26 October activation, with a devnet launch estimated for 16 to 20 November at the earliest, drawn up before the competing proposals arrived
Ethereum Developers Propose Two Fixes After Eight Contract Vulnerabilities Surface
Ethereum Foundation developer Marius van der Wijden confirmed in a 6 November statement that the Foundation was working with ChainSecurity and Dedaub to examine affected applications. The Foundation released a GitHub repository detailing each of the eight broken invariants with explanations, examples and self-check prompts for developers.
Curve Finance founder Michael Egorov warned of a possible emergency hard fork, writing that developers should not break the chain. Security researcher pcaversaccio argued that the upgrade should not ship in its current form.
Ryan Berckmans, an Ethereum community member and investor who initially backed moving ahead, withdrew that support. On 8 November, developers Leo Glisic and Giulio Rebuffo submitted competing fixes. Glisic’s EIP-8488 would add a separate set of V2 opcodes for newly deployed contracts that follow the revised pricing, allowing older contracts to keep their original gas schedule.
Rebuffo’s draft would run two gas accounting systems within each transaction, one tracking gas under previous rules and the other calculating the actual fee under the new schedule. Rebuffo’s draft states that no client implementation or consensus tests have been run. Both remain drafts with no target date.
Ethereum’s Gas Repricing Plan Puts Legacy Smart Contract Compatibility at Risk
The gas repricing is designed to let Ethereum support roughly three times its current base throughput by aligning costs with actual computational work. That goal sits at the centre of the Glamsterdam roadmap, which targets Layer 1 scalability improvements ahead of the follow-up upgrade, Hegota.
The tension is structural. Ethereum hosts billions of dollars in DeFi protocols whose contracts were written under gas assumptions that the repricing would change. The two competing proposals represent fundamentally different philosophies: Glisic’s approach preserves the old rules for existing contracts, while Rebuffo’s attempts to run both systems simultaneously.
Hoodi Testnet Upgrade Remains Delayed as Developers Review Competing Fixes
ChainSecurity’s 13 October report set out how the gas changes could break existing contracts. The concerns extend to prominent protocols and applications holding user funds.
The Hoodi testnet fork will not proceed until the compatibility issues are resolved, the Ethereum Foundation confirmed. The outcome of upcoming All Core Developers discussions will determine whether Glamsterdam ships with the original gas schedule, one of the two competing fixes, or a hybrid approach.
