A conveyor belt tensioning arrangement for an agricultural harvesting header (102) and the agricultural harvesting header (102) with the conveyor belt tensioning arrangement are described herein, the arrangement comprising a conveyor belt roller (208) supported on a roller carriage (228), the conveyor belt roller (208) being spring-loaded to maintain tension in the conveyor belt (108, 112), the conveyor belt roller (208) also being supported to pivot about an axis generally perpendicular to the longitudinal extent of the conveyor belt roller (208).