An agricultural harvester (100) comprises a self-propelled vehicle (102); a feederhouse (104); a driveshaft (114) supported on the feederhouse (104), the driveshaft (114) having a first coupler (116) fixed to one end of the driveshaft (114), the first coupler (116) comprising a coupler body (420), a piston (416) disposed in the coupler body (420), and a first key (302) mechanically coupled to the piston (416) to be extended or retracted by the piston (416) to engage a mating coupler on a second driveshaft (120) of an agricultural harvesting head (106) that is supported on the feederhouse (104).