Provided herein are multispecific antigen-binding polypeptide constructs comprising at least two different heterodimers, each comprising a heavy chain and a light chain. At least one heterodimer comprises a Fab region comprising a lambda light chain and at least one heterodimer comprises a Fab region comprising a kappa light chain. One or more of the immunoglobulin heavy and light chains that form the antigen-binding polypeptide construct comprise amino acid modifications that promote correct pairing between the heavy and light chains to form the desired multispecific antigen-binding polypeptide construct. The amino acid modifications may be in the CH1 and/or CL domains, in the VH and/or VL domains, or a combination thereof.
