There is provided an injection device for delivering a medicament from a container. The device includes, a housing for housing a container, a plunger substantially housed within the housing and which is movable within the housing, a force applicator for applying a force to the plunger, a trigger coupled to the force applicator for releasing the force applicator to fire the device, a boot, a dose selector for allowing a user to select a dose of medicament, and a first mechanical interlock arranged such that the force applicator cannot be released until the dose selector has been operated to select the dose of medicament, and a second mechanical interlock arranged such that the dose selector cannot be operated to select the dose of medicament prior to removal of the boot.