A method for controlling a vapour compression system, the vapour compression system comprising a compressor unit comprising one or more compressors (11, 12, 16), a heat rejecting heat exchanger, an ejector, a receiver, an expansion device and an evaporator arranged in a refrigerant path, wherein an outlet of the heat rejecting heat exchanger is connected to a primary inlet of the ejector, an outlet of the ejector is connected to the receiver and an outlet of the evaporator is selectively connected to a secondary inlet of the ejector and/or to an inlet of the compressor unit, and wherein a gaseous outlet of the receiver is connected to an inlet of the compressor unit, characterized in that the method comprises the steps of: - detecting a pressure of refrigerant leaving the evaporator, - detecting a state of the compressor unit, said state of the compressor unit indicating whether or not refrigerant is supplied from the outlet of the evaporator to the inlet of the compressor unit, - in the case that the step of detecting a state of the compressor unit reveals that refrigerant is supplied from the outlet of the evaporator to the inlet of the compressor unit, operating the compressor unit in order to decrease a pressure inside the receiver, - in the case that the step of detecting a state of the compressor unit reveals that refrigerant is not supplied from the outlet of the evaporator to the inlet of the compressor unit, comparing the detected pressure of refrigerant leaving the evaporator to a lower threshold value and to an upper threshold value, and - operating the compressor unit in order to: - increase a pressure inside the receiver in the case that the detected pressure of refrigerant leaving the evaporator is below the lower threshold value, - decrease a pressure inside the receiver in the case that the detected pressure of refrigerant leaving the evaporator is above the upper threshold value, and - maintain a pressure inside the receiver in the case that the detected pressure of refrigerant leaving the evaporator is between the lower threshold value and the upper threshold value. - detecting a pressure of refrigerant leaving the evaporator, - detecting a state of the compressor unit, said state of the compressor unit indicating whether or not refrigerant is supplied from the outlet of the evaporator to the inlet of the compressor unit, - in the case that the step of detecting a state of the compressor unit reveals that refrigerant is supplied from the outlet of the evaporator to the inlet of the compressor unit, operating the compressor unit in order to decrease a pressure inside the receiver, - in the case that the step of detecting a state of the compressor unit reveals that refrigerant is not supplied from the outlet of the evaporator to the inlet of the compressor unit, comparing the detected pressure of refrigerant leaving the evaporator to a lower threshold value and to an upper threshold value, and - operating the compressor unit in order to: - increase a pressure inside the receiver in the case that the detected pressure of refrigerant leaving the evaporator is below the lower threshold value, - decrease a pressure inside the receiver in the case that the detected pressure of refrigerant leaving the evaporator is above the upper threshold value, and - maintain a pressure inside the receiver in the case that the detected pressure of refrigerant leaving the evaporator is between the lower threshold value and the upper threshold value. - increase a pressure inside the receiver in the case that the detected pressure of refrigerant leaving the evaporator is below the lower threshold value, - decrease a pressure inside the receiver in the case that the detected pressure of refrigerant leaving the evaporator is above the upper threshold value, and - maintain a pressure inside the receiver in the case that the detected pressure of refrigerant leaving the evaporator is between the lower threshold value and the upper threshold value.