The present invention relates to cap (21) for an injection device (20). The cap (21) comprises a needle shield (22) and a conduit (31). The needle shield (22) comprises a body (24) with a recess (25) for receiving part of a needle syringe (18). The conduit (31) is movable from an initial position, wherein a portion of the body (24) is located between the recess (25) and the conduit (31), to a cap removal position, wherein the conduit (31) extends through said portion of the body (24) to fluidly communicate with the recess (25) to allow the ingress of gas into the recess (25).
