The invention relates to a method of controlling transient behaviour of an internal combustion engine (10) being provided with a turbocharger (110) and a variable inlet guide vanes assembly (130) arranged upstream a compressor (120) of the turbocharger (110). The method comprises determining a current operational condition indicative of transient behaviour, and, if said transient behaviour requires compressor acceleration: determining a desired operational condition of the compressor (120), and controlling the position of the variable inlet guide vanes assembly (130) based on the desired operational condition of the compressor (120).