A commonly used technique to implement polytypic programming is specialization, where a specialized version of a polytypic function is generated for every datatype it is used at. In this paper we describe an alternative technique that allows polytypic functions to be defined using Haskell’s class system (extended with multi-parameter type classes and functional dependencies). This technique brings the power of polytypic programming inside Haskell allowing us to define a Haskell library of polytypic functions. It also increases our flexibility, reducing the dependency on a polytypic language compiler.