A turboshaft engine including a low-pressure compressor, a high-pressure compressor, a low-pressure turbine, a high-pressure turbine, and a regulator for regulating a speed of rotation of the low-pressure turbine to a speed that is substantially constant. The low-pressure turbine is coupled by a first shaft to the high-pressure compressor, while the high-pressure turbine is coupled by a second shaft to the low-pressure compressor.