Celtic are back in the Champions League after their Polish opponents Legia Warsaw were disqualified for using a player they shouldn't have.
In the previous round, Legia had beaten the Scottish champions 6-1 when the scores were added together after two matches.
But they brought on a substitute to play while he was supposed to be suspended.
Celtic will now play Slovenian champions Maribor in the next round.
BBC Sport's John Watson explains what happened.