A method of a fingerprint sensing system of suppressing impairment data present in an image captured by a fingerprint sensor of the fingerprint sensing system , comprising: capturing (S101) a plurality of images of a fingerprint of a finger contacting the fingerprint sensor , the images comprising impairment data caused by impairments that the fingerprint sensor is subjected to; creating (S101a), by averaging the plurality of captured images of the fingerprint, an image comprising the impairment data ; storing (S102) the created image comprising the impairment data; repeatedly (S105) capturing new images of the fingerprint of the finger during normal user operation of an electronic device in which the fingerprint sensing system is arranged, the images comprising impairment data ; the method being characterized in comprising: creating (S106a), by averaging the captured new images and the previously stored image comprising the impairment data, an updated image comprising the impairment data; storing (S106b) the updated image comprising the impairment data; capturing (S103) at least one further image of the fingerprint of the finger contacting the fingerprint sensor ; and processing (S104) the further captured image of the fingerprint with the stored updated captured image comprising the impairment data in order to at least partly suppress the impairment data in said further captured image of the fingerprint. capturing (S101) a plurality of images of a fingerprint of a finger contacting the fingerprint sensor , the images comprising impairment data caused by impairments that the fingerprint sensor is subjected to; creating (S101a), by averaging the plurality of captured images of the fingerprint, an image comprising the impairment data ; storing (S102) the created image comprising the impairment data; repeatedly (S105) capturing new images of the fingerprint of the finger during normal user operation of an electronic device in which the fingerprint sensing system is arranged, the images comprising impairment data ; the method being characterized in comprising: creating (S106a), by averaging the captured new images and the previously stored image comprising the impairment data, an updated image comprising the impairment data; storing (S106b) the updated image comprising the impairment data; capturing (S103) at least one further image of the fingerprint of the finger contacting the fingerprint sensor ; and processing (S104) the further captured image of the fingerprint with the stored updated captured image comprising the impairment data in order to at least partly suppress the impairment data in said further captured image of the fingerprint. creating (S106a), by averaging the captured new images and the previously stored image comprising the impairment data, an updated image comprising the impairment data; storing (S106b) the updated image comprising the impairment data; capturing (S103) at least one further image of the fingerprint of the finger contacting the fingerprint sensor ; and processing (S104) the further captured image of the fingerprint with the stored updated captured image comprising the impairment data in order to at least partly suppress the impairment data in said further captured image of the fingerprint. <EOS>