A vehicle comprising a combustion engine, a WHR-system, and a cooling system, wherein the cooling system comprises - a radiator line directing coolant through a radiator in which the coolant is cooled to a first temperature (t 1), - a radiator bypass line directing coolant past the radiator, - a condenser line receiving coolant from the radiator line and/or the radiator bypass line and directing the coolant through a condenser of the WHR system, - a condenser bypass line receiving coolant from the radiator line and/or the radiator bypass line and directing the coolant past the condenser, - a thermostat receiving a coolant flow range (m) at a second temperature (t 2), wherein the thermostat in a closed position directs the entire coolant flow range (m) to the radiator bypass line, in a partly open position directs a first coolant flow range ṁ 1) to the radiator line and a second coolant flow range (ṁ 2) to the radiator bypass line, and in a fully open position directs the entire coolant flow rate (m) to the radiator line, wherein the cooling system comprises - a valve arranged in the condenser bypass line by which it is possible to adjust the flow resistances in the condenser bypass line in relation to the flow resistance in the condenser line and thus the coolant flow rate (ṁ 4) through the condenser bypass line in relation to the coolant flow rate (ṁ 3) through the condenser line and - a control unit configured to control the valve such that the coolant directed to the condenser has a temperature and a flow rate which results in a cooling of the working medium in the condenser to a desired condensation temperature/pressure at the actual operating condition, characterized in that the control unit is, during operating conditions when the thermostat is in a partly open position, configured to estimate a desired cooling temperature of the working medium in the condenser, calculate the coolant flow rate (ṁ 1) through the radiator line and the coolant flow rate (ṁ 2) through the radiator bypass line, calculate a coolant flow rate (ṁ 3) and coolant temperature (t 3) combination at which the medium in the condenser is cooled to the desired temperature, and to adjust the valve such that coolant at the selected flow rate (ṁ 3) and temperature (t 3) combination is directed to the condenser line and the condenser. - a radiator line directing coolant through a radiator in which the coolant is cooled to a first temperature (t 1), - a radiator bypass line directing coolant past the radiator, - a condenser line receiving coolant from the radiator line and/or the radiator bypass line and directing the coolant through a condenser of the WHR system, - a condenser bypass line receiving coolant from the radiator line and/or the radiator bypass line and directing the coolant past the condenser, - a thermostat receiving a coolant flow range (m) at a second temperature (t 2), wherein the thermostat in a closed position directs the entire coolant flow range (m) to the radiator bypass line, in a partly open position directs a first coolant flow range ṁ 1) to the radiator line and a second coolant flow range (ṁ 2) to the radiator bypass line, and in a fully open position directs the entire coolant flow rate (m) to the radiator line, wherein the cooling system comprises - a valve arranged in the condenser bypass line by which it is possible to adjust the flow resistances in the condenser bypass line in relation to the flow resistance in the condenser line and thus the coolant flow rate (ṁ 4) through the condenser bypass line in relation to the coolant flow rate (ṁ 3) through the condenser line and - a control unit configured to control the valve such that the coolant directed to the condenser has a temperature and a flow rate which results in a cooling of the working medium in the condenser to a desired condensation temperature/pressure at the actual operating condition,