The present invention relates to a modified enzyme which comprises a catalytically active amino acid sequence of a cellulolytic enzyme linked to an amino acid sequence comprising a Cellulose Binding Domain (CBD) having a relative binding constant (Kr-a) for binding to amorphous cellulose higher than 2.4 l/gcellulose, preferably higher than 3.5 l/gcellulose, more preferably higher than 4 l/gcellulose, for selective binding and hydrolysis of amorphous cellulose of cotton containing fabrics in a laundry and/or fabric care application. The present invention further relates to laundry detergent and/or fabric care compositions comprising this modified enzyme.