The invention concerns a device for stopping a leak in a pipe having at least one crack (12, 12'), comprising an elastomer sheet (14) applied against the crack with a force applicator (16) and a clamping mechanism (20, 22) arranged around the pipe for applying a force on the force applicator. Said force applicator comprises shearing elements (40, 42) preferably consisting of a first group of rigid parallel partitions (40) and a second group of parallel partitions (42) arranged perpendicularly to the partitions of the first group, said partitions being arranged perpendicularly to the pipe and applying shearing efforts on the elastomer sheet on the site of the crack, forcing the elastomer to be deformed so as to match the shape of the crack, thereby stopping it.