Let \(\tau\) be a type of algebras. By a hypersubstitution of type \(\tau\) there is either meant a mapping assigning to every fundamental operation symbol of type \(\tau\) a term of type \(\tau\) of the same arity or there is meant the obvious extension of this mapping to the set of all terms of type \(\tau\). The main result of this paper is the following: Up to equivalence there is only one non-trivial hypersubstitution of type \((2,2,1,0,0)\) which is proper with respect to the variety of orthomodular lattices, namely the one which interchanges the binary as well as the nullary operations and leaves the unary operation fixed.