Ethereum founder Vitalik Buterin has clarified his remarks on the expected launch date of Eth 2.0.

During a Monday appearance at CoinDesk’s Consensus: Distributed, Buterin appeared to confirm a July launch date put forth in February by the lead researcher of the Eth. 2.0 project, Justin Drake.

CoinDesk Chief Content Officer Michael J. Casey asked if the overhaul to the world's second-largest cryptocurrency by market cap was "really coming in July. Are we ready for it?"

"I think so, yeah," Buterin said, before rattling off milestones achieved so far.

Eth 2.0 testnet coordinator Afri Schoedon countered Buterin’s statements on Twitter. “The final spec is not implemented in any client and we didn’t launch a coordinated testnet yet,” he wrote, adding:

In response, Buterin tweeted, “Yeah I did not say July. Perhaps the question contained the word July but I did not hear July when it was asked.” He then sent a second tweet, saying, “OK I definitely should have heard July in the question, it was my mistake.”

Schoedon is coordinating the Schlesi multi-client testnets, one of many test versions of the overhaul preceding Eth 2.0’s eventual launch. He has said Eth 2.0 Phase 0 could launch as late as 2021.

When reached by CoinDesk on Tuesday, Buterin offered a statement:

Eth 2.0 represents a fundamental shift from a proof-of-work (PoW) consensus algorithm like Bitcoin’s to proof-of-stake (PoS).

The transition, which was included in the early plans of Ethereum, has grown to be a contentious topic following delays and missed deadlines.

Watch the full exchange from Consensus: Distributed: