Child safety seat with a motorized harness belt tensioner

A child safety seat comprising:

• an integral harness belt for restraining a child in the child safety seat,
• a motorized harness belt tensioner comprising a tensioning element driven by an electro-mechanical actuator and adapted for adjusting the belt tension acting on the harness belt,
• a controller adapted for controlling the motorized harness belt tensioner to adjust the belt tension to match a first predefined belt tension, the controller being adapted for controlling the motorized harness belt tensioner to increase the belt tension from the first predefined belt tension to a second predefined belt tension upon receiving a first trigger signal indicating a potential imminent accident of a vehicle in which the child safety seat is installed.