An injection device 110 is described having a housing 112 and a cap 130. The injection device 110 houses a syringe 114 having a needle which is sealed by a boot 118. The cap 130 is arranged so that the boot 118 can be connected to the cap 130 while exerting a minimal force on the syringe, but cannot be removed from the cap 130 without applying a significantly greater force to the syringe. The housing 112 and cap 130 are arranged so that upon removal of the cap 130 from the housing 112, the boot 118 is removed from the syringe 114.
