A bakery worker at the Warburtons bakery in Bellshill, who stabbed a colleague through the heart in a row over tea breaks, was jailed for life on Monday.
Paul Steadward must serve a minimum of 16 years in prison before being considered for parole, said the judge.
He had denied murdering Steven McArdle on 8 March last year, claiming self-defence.
The court heard that Steadward and McArdle, during a 12-hour shift, had rowed over the length of time McArdle was taking for tea breaks at the bakery. Shortly after the argument, Steadward followed him outside with a 10-inch knife.