An adaptor for connecting a second connector to a drug delivery device includes at least a container for a product, the container including a distal tip and an axial passageway defined through the distal tip, the adaptor having a longitudinal axis and being intended to be mounted on the distal tip, the adaptor including a first part and a second part, the first part being provided with an unreleasable attachment able to fix the first part to the distal tip, the second part being provided with a connector able to connect the second part to the second connector, the adaptor further including a securer able to anchor the first part to the second part. The drug delivery device includes the adaptor and a method for mounting the adaptor.
