A corrugated tube that can be folded open, for holding cables, comprises: first and second corrugated tube shells, which have a respective plurality of first and second corrugated tube ribs extending peripherally around the respective corrugated tube shell, a joint section, which separates the corrugated tube ribs from each other and pivotably connects the corrugated tube shells to each other, at least one lip section, which is provided on at least one of the corrugated tube shells, and a locking device for locking the two corrugated tube shells to each other when the corrugated tube is brought from a folded-open state into a folded-together state. The locking device includes the corrugated tube ribs, and in the folded-together state, the second corrugated tube ribs extend around the first corrugated tube ribs interlockingly both in a radial direction and in a peripheral direction of the corrugated tube.