A retaining band is provided for a container, e.g. for a joint between a flexible plastics pouring spout and a container neck, or for a lidded drum or pail. The band is movable from an expanded position in which it can be placed over the container with a clearance fit, to a constricted position in which the band tightly engages about the container. The band comprises a detent formed by a toothed spigot lockingly receivable in a toothed receptacle that are mechanically interengageable to prevent movement of the band from the constricted position towards the expanded position. The band may be formed as a separate component or as an integral part of a closure, the spout or the container.