Aerosol can introduce significant errors in measurements of trace gas concentration profiles with the Differential Absorption Lidar (DIAL). Here, a solution to counteract the aerosol effect is introduced which does not depend on additional measurements and is applicable when absorption at the off-wavelength is not negligible. It is based on a numerical solution of the coupled lidar equations and calculates the trace gas concentration and the aerosol backscatter ratio simultaneously. Consequently, most of the errors introduced by aerosols to DIAL measurements are inherently corrected and additionally, the aerosol backscatter profiles at the DIAL wavelengths are obtained.