A drug delivery device includes a housing, a container disposed in the housing, an activation mechanism, a needle insertion mechanism, a fluid flow connection, and a valve in fluid communication with the fluid flow connection and the needle insertion mechanism. The container has an inner volume to contain a medicament which is urged out of the container by the activation mechanism. The needle insertion mechanism is adapted to insert a needle and/or a cannula to deliver the medicament from the container via the fluid flow connection. The valve is in fluid communication with the fluid flow connection and needle insertion mechanism, and is movable between first and second positions. Upon insertion of the needle and/or the cannula, the valve remains in the first position whereby fluid flow is restricted. At a later time, the valve is urged to the second position whereby fluid may flow through the needle or cannula.