South Dakota Governor Kristi Noem, a Republican, on Friday returned to lawmakers a controversial bill that bars transgender girls and women from participating in female sports.

After lawmakers approved House Bill 1217 earlier this month, Noem tweeted that she was “excited to sign this bill very soon.”

But on Friday, Noem announced a so-called “Form and Style” veto of the bill, sending the legislation back to lawmakers.

“Unfortunately, as I have studied this legislation and conferred with legal experts over the past several days, I have become concerned that this bill's vague and overly broad language could have significant unintended consequences,” Noem said in a statement.

Noem's proposed changes include removing college athletes from the ban, deleting the requirement that every school submit waivers documenting a student's “reproductive biology,” and adding the use of an affidavit to define “biological sex.”

The bill's backers balked at the request, saying that the changes substantially alter the legislation.

“Legislators are the ones who make the laws and the governor signs them,” Representative Rhonda Milstead, a Republican from Hartford and the bill's prime sponsor in the House, told the Argus Leader. “She's gutting the bill and writing a new law and that's not her job.”

Earlier this month, Tate Reeves, the Republican governor of Mississippi, signed a similar measure into law.

The legislation – with Noem's amendments – needs only a simple majority in both houses to become law.