In a device for adjusting the crop material passage at the post-accelerator in an agricultural harvesting machine, in particular in a self-propelled forage harvester that includes at least one front attachment for picking up the crop material, and that is assigned to at least one processing device, the crop material handed off by the processing device passes through at least one post-accelerator, which is at least partially enclosed by a machine housing and is movable relative to the machine housing via a displacing mechanism, while the post-accelerator is fixed on the machine housing is position such that it is decoupled from the displacing mechanism.