The present invention relates to a polypeptide having proline-specific endoprotease activity, wherein the polypeptide has less than 70% residual activity when the polypeptide has been kept at a temperature of 65° C. for 15 min.The invention further relates to a polypeptide having proline-specific endoprotease activity comprising an amino acid sequence according to SEQ ID NO: 1, wherein SEQ ID NO: 1 comprises at least one amino acid substitution selected from the group consisting of P469A, P469C, P469D, P469E, P469F, P469G, P469H, P469I, P469K, P469L, P469M, P469N, P469Q, P469R, P469S, P469T, P469V, P469W, P469Y, a nucleic acid encoding a polypeptide having proline-specific endoprotease activity, a method of making a variant polypeptide having proline-specific endoprotease activity, a recombinant host cell and a method of producing the polypeptide and a process for the preparation of a food or feed product wherein the polypeptide is used.