An inkjet printer and a method for controlling an inkjet printer are disclosed. The inkjet printer is provided with an endless transport belt for transporting a medium to be printed; at least one roller for driving the transport belt and at least one additional roller for driving and/or suspending the transport belt; a detection system configured to detect a deformation of the transport belt including at least an in-plane bending deformation of at least a stretch of the transport belt and to generate at least one deformation signal indicating the detected deformation; an actuator assembly configured to change a position and/or orientation of at least one of the rollers of the inkjet printer; and a controller configured to control the actuator assembly based on the at least one deformation signal.