  The Maxwell field can be viewed as a $U(1)$-gauge theory, therefore,
generalizing it to form-invariance in dynamical spacetime backgrounds should
take this symmetry into account. This is of essential importance when
generalizations of general relativity to theories with non-vanishing torsion
are considered. Despite the many statements in literature that a $U(1)$-gauge
field cannot couple to torsion, this issue was recently revived. In this letter
we contribute to the discussion by demonstrating via a canonical transformation
within the framework of the DeDonder-Weyl Hamiltonian formalism that a
$U(1)$-gauge field does not couple to torsion.
