A urea injection control system for an internal combustion engine ICE, the ICE arranged in relation to an exhaust gas aftertreatment system EATS, the urea injection control system comprising: - a urea injector adapted to inject urea into an exhaust line of the ICE, the exhaust line arranged in fluid communication with a selective catalytic reduction SCR catalyst of the EATS, and - a control unit, wherein the control unit is adapted to: - select a first flow rate of urea injection based on a present operational condition of the ICE, - determine a present operational region of a plurality of predefined operational regions for the ICE, - select an adaptation factor for the present operational region, - form a second flow rate of urea injection based on the first flow rate of urea injection and the selected adaptation factor, - control the urea injector according to the second flow rate of urea injection, - receive an indication of a NOx level downstream of the SCR catalyst, and - adjust the adaptation factor for the present operational region to decrease the NOx level downstream of the SCR catalyst, wherein the control unit is further adapted to: - determine the present operational region based on a combination of at least two intermediate operational parameters for the ICE, wherein the at least two intermediate operational parameters for the ICE are selected from a group comprising an exhaust temperature, an exhaust mass flow through the EATS, revolutions per minute for the ICE, a torque value for the ICE, an estimated NOx level generated by the ICE, a urea concentration, an ambient temperature in relation to the ICE, an ambient humidity level in relation to the ICE, characterized in that the control unit is further adapted to: - receive an indication of a NOx level upstream of the SCR catalyst, and - adjust the adaptation factor for the present operational region to increase a NOx conversion performance, the NOx conversion performance determined based on the indication of the NOx level upstream of the SCR catalyst and the indication of the NOx level downstream of the SCR catalyst. - a urea injector adapted to inject urea into an exhaust line of the ICE, the exhaust line arranged in fluid communication with a selective catalytic reduction SCR catalyst of the EATS, and - a control unit, - select a first flow rate of urea injection based on a present operational condition of the ICE, - determine a present operational region of a plurality of predefined operational regions for the ICE, - select an adaptation factor for the present operational region, - form a second flow rate of urea injection based on the first flow rate of urea injection and the selected adaptation factor, - control the urea injector according to the second flow rate of urea injection, - receive an indication of a NOx level downstream of the SCR catalyst, and - adjust the adaptation factor for the present operational region to decrease the NOx level downstream of the SCR catalyst, - determine the present operational region based on a combination of at least two intermediate operational parameters for the ICE, wherein the at least two intermediate operational parameters for the ICE are selected from a group comprising an exhaust temperature, an exhaust mass flow through the EATS, revolutions per minute for the ICE, a torque value for the ICE, an estimated NOx level generated by the ICE, a urea concentration, an ambient temperature in relation to the ICE, an ambient humidity level in relation to the ICE, - receive an indication of a NOx level upstream of the SCR catalyst, and - adjust the adaptation factor for the present operational region to increase a NOx conversion performance, the NOx conversion performance determined based on the indication of the NOx level upstream of the SCR catalyst and the indication of the NOx level downstream of the SCR catalyst.