Walstad began the 2018–19 curling season in the first leg of the Curling World Cup, where he lost in the final to Canada's Kevin Koe. The next month, the Walstad rink played in their second slam, the 2018 Masters. There he was less fortunately, losing all of his games. In November, the team played in the 2018 European Curling Championships, where Waldstad led Norway to a 5–4 record in fifth place. In the New Year, the team played in the third leg of the Curling World Cup, where they had less success, finishing in 6th. Later in the season, Walstad was named as the alternate on the Norwegian team, skipped by Magnus Ramsfjell at the 2019 World Men's Curling Championship. The team finished in 12th place.