The House passed legislation today that would force President Donald Trump to slap sanctions on Turkey over its purchase of the Russian S-400 missile defense system.

House lawmakers unanimously adopted the bipartisan amendment, introduced by Reps. Adam Kinzinger, R-Ill., and Abigail Spanberger, D-Va., as part of the annual defense authorization bill, which passed 295-125 today.

“Turkey ignored warnings from NATO members about this arms deal with Russia and accepted their first installment of the Russian-made S-400 missile defense system,” Kinzinger said in a statement upon introducing the legislation last week. “We need to make it very clear that their actions will not be tolerated and will be met with serious consequences. Our legislation does that and makes the actions by Turkey an explicitly sanctionable offense.”

Why it matters: Turkey tested the powerful S-400 radar on US fighter jets last year, stoking fears that Russia could spy on American military hardware. The Trump administration has refused to place legally mandated sanctions on Turkey over the S-400 missiles despite pressure to do so from some of the president’s closest Republican allies in Congress. The 2017 Countering America’s Adversaries Through Sanctions Act (CAATSA) mandates penalties on any country that engages in a “significant transaction” with the Russian defense sector.