Ethereum’s next upgrade, Fusaka, just moved closer to going live on the main blockchain after a successful test run on the Holesky test network early Wednesday.

The Fusaka hard fork comes only a few months after Ethereum’s major Pectra upgrade and is designed to make things cheaper for institutions using Ethereum. One of the changes it introduces is PeerDAS, a feature that lets validators check only part of the data needed instead of full chunks (“blobs”), which helps cut costs for both layer-2 networks and validators.

Test networks like Holesky act as practice grounds where developers can safely test new code before it reaches the real chain. Holesky, launched in 2023, was particularly important because its validator setup closely mirrors Ethereum’s mainnet. But over the past few months, Holesky has started showing signs of age and reliability issues. Fusaka is the last upgrade the network will see before it shuts down — two weeks after Fusaka goes live on mainnet.

The next two testnet runs are scheduled for Oct. 14 and 28. After those are complete, Ethereum developers will lock in a date for Fusaka’s full mainnet launch.

“Holesky finalized! A great first step towards Fusaka on mainnet and to more blobs on Ethereum,” said Ethereum Foundation DevOps engineer Parithosh Jayanthi on X.

Read more: Ethereum to Close Its Largest Testnet, Holesky, After Fusaka Upgrade