Two U.S. banking regulators on Tuesday approved changes easing a rule introduced after the 2007-2009 financial crisis that bans banks from trading on their own account, giving Wall Street one of its biggest wins under the Trump administration.

The Office of the Comptroller of the Currency (OCC) and the Federal Deposit Insurance Corporation (FDIC) approved the final version of the so-called “Volcker Rule,” which aims to ban lenders that accept U.S. taxpayer-insured deposits from engaging in proprietary trading.

The changes, first proposed in May 2018, followed years of lobbying by banks, including Goldman Sachs Group (GS), JPMorgan Chase (JPM) and Morgan Stanley (MS), which have long complained the rule is too vague and complex.

While many regulatory experts also agree the rule is too cumbersome, the proposed changes have been criticized by consumer groups and Democratic lawmakers who say a rewrite could create new systemic risks. Analysts say the final rule, which is significantly different from the proposed 2018 version, could also be vulnerable to legal challenges.

The rewrite aims to clarify which trades qualify for safe harbors, such as when banks facilitate client trades and hedge risks, and to expand those exemptions. The final rewrite scraps a proposed new test for identifying proprietary trading that banks complained would have made the rule even more complicated.

That proposed “accounting test” was meant to help define what trading fell under the safe habor for facilitating client trades, replacing a more subjective test that aims to identify whether a trader intended a trade to be speculative. But banks argued it could apply to a host of additional financial instruments not meant to be covered by the rule.

The final rule scraps that proposal and in turn simplifies the original test to apply to firms with just $1 billion in trading assets, giving relief to all the major Wall Street firms.

At the same time, the rewrite simplifies a separate part of the rule which makes it easier for banks to invest in hedge funds or private equity funds. Regulators said they expect to propose further easing of the “covered funds” aspect of the rule, including for foreign firms, later this year.

The rule will become effective on Jan. 1, 2020, but banks will have one year to comply.

The OCC and the FDIC are two of five regulators charged with implementing the rule. The others - the Federal Reserve, the Securities and Exchange Commission, and the Commodities Futures Trading Commission - are expected to approve the new rule soon.