Disclosed is an injection device for receiving a syringe therein and for delivering a dose of medicament from the syringe, the injection device including: an insertion driver configured to drive the syringe forwards within the injection device for inserting a needle of the syringe into an injection site; an interlock mechanism configured to retain the insertion driver in a primed state and, when actuated, to allow the insertion driver to drive the syringe forwards; and an interlock actuator moveable between a stowed position and an operable position and configured on movement from the stowed position to the operable position to couple to an actuation system such that movement from the operable position back towards the stowed position actuates the interlock mechanism.