Senator Rob Portman, one of the lead Republican voices for negotiations over an infrastructure bill in the United States Senate, said he supports an amendment clarifying the intent of a cryptocurrency provision.

In a tweet today, Portman encouraged his colleagues in the Senate to vote on an amendment proposed this week by Ron Wyden, Cynthia Lummis and Pat Toomey that suggests striking the definition of brokers in the infrastructure bill to no longer include developers, miners or blockchain firms in the crypto space.

The senator’s stance is somewhat surprising, given he has previously supported the language used in the bill, saying on Tuesday that the legislation “does not impose new reporting requirements on software developers, crypto miners, node operators or other non-brokers” and calling the section on brokers a “common-sense provision.” Ted Cruz, the junior Senator from Texas, also reportedly put forth an amendment to strike the provision.

The bill, HR 3684, includes funding for roads, bridges and major infrastructure projects, as well as proposes implementing tighter rules on businesses handling cryptocurrencies, expanding reporting requirements for brokers and mandating that digital asset transactions worth more than $10,000 are reported to the Internal Revenue Service. Majority leader Chuck Schumer is reportedly planning to attempt to keep the Senate in session — the government body is scheduled to be in recess from Aug. 9 — to vote on key amendments.

While the intent behind the bill seems to require crypto exchanges to report certain transactions, many lawmakers and opponents to the legislation immediately criticized the language, implying reporting requirements could potentially be extended to developers, node operators and miners.

Related: Ohio senator wants clarity for crypto tax reporting in proposed bill

According to digital rights advocacy group Fight for the Future, more than 9,000 activists have called to voice their support of the amendment proposed by Wyden, Lummis and Toomey. Industry membership body Global Digital Finance also said it would welcome the clarifying language, noting 114 signatories from the crypto and blockchain space had attached their names to a letter expressing support for the amendment.

Jeff Bandman, a board member of Global Digital Finance, said:

“Assuming the amendment is approved, it would serve to raise revenues from appropriate actors, promote regulatory certainty and allow innovators to continue to develop new financial products, many of which could enhance financial inclusion in the U.S., without fear of unwarranted tax liabilities.”

The amendment would require 60 votes to be added to the legislation. With Portman’s support, the amendment may be more likely to receive Republican votes in a U.S. Senate split evenly along party lines.