Americans proudly sang "The Star-Spangled Banner" on Thursday night ahead of the 4 Nations Face-Off final between the U.S. and Canadian hockey teams.

So, ahead of the highly-anticipated United States versus Canada matchup in the 4 Nations Face-Off, American fans booed the Canadian national anthem, seemingly in retaliation for Canadian fans booing the U.S. anthem earlier in the tournament. The boos were audible at the beginning of the anthem but were then drowned out by Canadian cheers.

As soon as the singer, Royal Canadian Air Force member David Grenon, began belting, “Oh, say, can you see,” the crowd at the Bell Centre in Montreal let out an aggressive and booming chorus of boos that nearly drowned out the anthem entirely.