Two top GOP lawmakers Friday sent a letter to the Department of Homeland Security, accusing the Obama administration of creating a “fraud loophole” for young people brought to the U.S. illegally.

House Judiciary Committee Chairman Bob Goodlatte, R-Va., and his Senate counterpart, Judiciary Committee ranking member Chuck Grassley, R-Iowa, said the administration “quietly made several changes” this summer to its Deferred Action for Childhood Arrivals program, known as DACA.

Obama authorized the program though executive action in 2012. It allows many young people who were brought to the U.S. illegally as children to avoid deportation and obtain work permits, as long as they meet certain requirements.

According to Goodlatte and Grassley, the administration has reduced DACA’s educational requirement. The administration, they added, has also weakened the language requiring the verification of documents provided by those applying for admittance in the DACA program.

“For any documentary evidence provided by an applicant to meet DACA requirements, officials now ‘may verify information,’ as opposed to actually verifying the veracity of the documents,” Grassley and Goodlatte said.

The two sent the letter to Homeland Security Secretary Jeh Johnson on Friday, asking questions about DACA, including whether gang members are using the program and information about people who were granted entry into DACA but were later stripped of their benefits.

“The American people deserve to understand why their own government would be encouraging fraud and potentially even helping some who want to do us harm game the system in order to do so,” wrote in the letter to Johnson.

In the letter, Goodlatte and Grassley recount a June 5 conference call between congressional staff and officials from the United States Citizenship and Immigration Services, which administers the DACA program.

A USCIS employee on the call, responding to questions about whether documentation is verified, suggested the government doesn’t check, saying, “generally the majority of documents we receive are valid.”

Goodlatte and Grassley also want Johnson to explain changes to the educational requirement for those admitted to the DACA program. The modification this summer included adding “alternative program,” to the list of ways DACA applicants can meet the education requirement.

“Please provide any communication between DHS and the Department of Education regarding the concept and definition of ‘alternative program,” the letter to Johnson states.

The letter also asks whether English classes that last only days or weeks meet the requirement.