The present disclosure relates to a class of engineered polypeptides having a binding affinity for albumin. In particular, the present invention relates to albumin binding polypeptides which have a high resistance to proteolytic cleavage and therapeutic use thereof. The disclosure provides an albumin binding polypeptide comprising an albumin binding motif, which motif consists of the amino acid sequence GXASDX5YKX8X9I X11X12AX14TVEGVX20 ALX23X24X25ILX28X29XB.