The Ethereum Glamsterdam upgrade is no longer scheduled to activate on the Hoodi testnet on October 26. Core developers removed the activation from Hoodi’s configuration after fresh research flagged how the upgrade’s gas-accounting changes could interact with existing smart contracts — the kind of deliberate pause the testing process exists to allow, even if it resets the calendar.
The decision was announced on October 22 via the Ethereum Foundation’s Protocol Cluster blog following the ACDE #248 call. Alongside the Amsterdam execution-layer activation, the Gloas consensus-layer activation was stripped from Hoodi’s configuration, and a planned testnet gas limit increase to 200 million was postponed with it.
Why the Ethereum Glamsterdam Upgrade Wait Continues
The trigger was ChainSecurity’s October 13 research into EIP-8037 and EIP-8038. Under the new state-growth-limiting rules, SSTORE gas refunds could leave contracts holding more or less gas than they expect — potentially turning caught, handled errors into permanent failures, or causing otherwise valid operations to revert. The numbers are not subtle: a new storage slot would cost 110,020 gas under the new rules versus 22,100 under the old ones.
In plain terms, the upgrade would have changed the price of storage in a way that some deployed contracts never planned for. Finding that on Hoodi instead of mainnet is the system working as intended.
What Happens Next for Glamsterdam
No replacement Hoodi date has been announced. Hoodi operators are told to revert to releases without the October 26 activation or install client builds whose notes confirm its removal, and developers should not plan testing around an October 26 activation. The Sepolia testnet completed its Glamsterdam activation on October 6 and is unaffected.
Mainnet remains the open question: no confirmed activation date exists, and a possible December 2026 target is still unconfirmed after the upgrade already slipped past its original first-half window. Glamsterdam will arrive when the gas math is settled — the Ethereum ecosystem has decided that once more beats shipping twice.
