Fox News reported that a pair of mischievous Swedish schoolgirls ended up in court for bugging their teachers’ staff room in a bid to get better grades, local media reported Tuesday.

The girls were only caught when one of them was so excited about the scam that she blabbed about it on her Facebook page, according to news website The Local.

The teenagers, who were not named, came up with the plan after finding a key to the teachers’ lounge. They then went to a spy shop, bought bugging equipment and planted it in the staff room the day before teachers were due to have a meeting about how to grade students’ work.

The pair reportedly thought the plot would give them an advantage on upcoming tests and school work — but after one of the girls mentioned their clever plan on Facebook, teachers found the bug.

The girls were charged with trespassing and fined 2,000 kronor ($270) each in Stockholm District Court.