 Langenus was selected to officiate at the 1928 Summer Olympics, and he refereed the first round match on 30 May 1928 at the Olympisch Stadion, where Uruguay beat the Netherlands by 2–0 in front of 40,000 people, and confirmed their place in the quarter-finals.He was then given the honour of controlling the Bronze Medal game, at the same venue on 10 June 1928, between Italy and Egypt, when the African side were soundly beaten by 11 goals to 3 (Schiavio, Banchero and Magnozzi all scored hat-tricks for the winning side).In the 1930 FIFA World Cup, held in Uruguay and the first ever to be staged, Langenus handled four matches as referee, plus two as linesman.