A method of operating an internal combustion engine

Disclosed is a method of operating an internal combustion engine 110 equipped with an aftertreatment device 280. The internal combustion engine 110 is equipped with a cylinder 125 having an exhaust gas port 220 intercepted by an exhaust valve 217. The exhaust valve 217 is actuated by means of a Variable Valve Actuation (VVA) system. The method comprises the steps of detecting an exhaust aftertreatment device 280 regeneration and closing the exhaust valve 217 early, during the aftertreatment device regeneration. The Variable Valve Actuation (VVA) system is used to provide an exhaust valve 217 actuation profile having an earlier exhaust valve 217 closure with respect to a baseline exhaust valve actuation profile. The VVA is used to control exhaust valve closing timing and thereby control the temperature of exhaust gas from the engine. An associated apparatus and computer program are also disclosed.