Nearly two dozen high-school seniors who were accepted by the University of Washington last spring but who then slacked off in school have had their offers of admission revoked, according to The Seattle Times.

The university, which reviewed admitted applicants’ final high-school transcripts over the summer, rescinded 23 offers of admission. In addition, 180 freshmen received letters from the university that rebuked them for a “significant downturn” in their academic performance at the end of high school, the newspaper said.

The students who had their admissions offers revoked fell into three main categories, the university’s director of admissions told the newspaper. One group’s transcripts had grades that plummeted from mostly A’s and B’s to C’s, D’s, and F’s by the end of senior year. Another group failed a required course, such as mathematics. Members of the final group had noted their enrollment in challenging high-school courses on their applications but later dropped them or failed to complete them.