TLDR
- Developers surveyed at TABconf expect Bitcoin’s next soft fork in 2028 or later.
- The leading candidate is BIP-54, also called the Great Consensus Cleanup.
- Co-author Matt Corallo gives BIP-54 an 80% chance of being the next soft fork.
- The upgrade would fix four known bugs, including the time warp flaw.
- LayerTwo Labs CEO Paul Sztorc called it a “janitorial maintenance fork.”
Bitcoin’s next protocol upgrade may not arrive until 2028 or later, according to developers surveyed at a recent industry conference. The leading candidate fixes four long-known bugs and does not add a new feature.
The proposal is called the Great Consensus Cleanup, or BIP-54. It was first put forward in 2019 and targets flaws in Bitcoin’s consensus rules that have been around for years.
Longtime Bitcoin developer Matt Corallo, a co-author of BIP-54, says there is an 80% chance it becomes the network’s next soft fork. He shared the estimate during an appearance on MARA Foundation TV with Isabel Foxen Duke, head of the MARA Foundation.
“There’s a laundry list of things we know of that we really need to clean up,” Corallo said. He added that the issues are real concerns but “not like, ‘Oh, the sky is falling.'”
Four Bugs on the Fix List
The first target is poison blocks. A miner could craft a special block that exploits performance bottlenecks, which would slow down validation for other nodes and give that miner a short-term edge.
The second is the time warp bug. A loophole in Bitcoin’s two-week difficulty adjustment window lets miners with a majority of hashrate manipulate block timestamps, which speeds up how fast new blocks are issued.
The third is Merkle malleability. A 64-byte transaction is the same size as an internal Merkle tree node, so an attacker could in theory forge proofs that trick light clients into accepting fake transactions.
The fourth involves duplicate coinbase transactions. Old design quirks allowed duplicate transaction IDs, and these will resurface at future block heights. That could overwrite existing coins or disrupt ledger accounting.
Corallo said BIP-54 “fixes some stuff that everyone agrees are problems.” None of the four issues is urgent, but each is a known weakness in the network.
A Test Run for Activation
Corallo also sees BIP-54 as practice. Many current Bitcoin developers have never worked through a soft fork, and the last one, Taproot, activated in 2021.
Taproot’s rollout came after months of debate over how it should be activated. The arguments pitted miner signaling thresholds against mandatory user flag days.
“In every recent soft fork, there’s also been a bunch of drama about activation mechanisms,” Corallo said. He hopes the community can settle that process once, then “copy and paste and reuse it” for future upgrades.
Since Taproot, other proposals have stalled. Changes such as OP_CAT (BIP-347) and OP_CHECKTEMPLATEVERIFY (BIP-119) have struggled to reach ecosystem-wide consensus, often framed as a debate over “ossification.”
Corallo said soft forks have always involved technical hurdles. More recently, he has seen political and social friction become just as relevant.
Not everyone is enthusiastic about the plan. Paul Sztorc, co-founder and CEO of LayerTwo Labs, wrote on X that BIP-54’s potential activation is “kind of depressing, since it is a janitorial maintenance fork that doesn’t do anything.”
Yesterday, the TabConf Elite weighed in on SFD, the date of Bitcoin's next soft fork *activation*.
(This is the Bitcoin version of P(doom).)
These were the reports, of the best and brightest:
Sept 1, 2027
Dec 31, 2027
Feb 17, 2028
Mar 1, 2028
June 15, 2028
Dec 31, 2028
Dec 31,…— Paul Sztorc (@Truthcoin) October 13, 2026
Sztorc also surveyed developers at TABconf in Atlanta. He said most expect the Great Consensus Cleanup to be the next soft fork, with the earliest estimate in September 2027 and most pointing to 2028 or later.
