We present an evaluation of the π ± and K ± box-contributions to the hadronic light-by-light piece of the muon's anomalous magnetic moment, aµ. The calculation of the corresponding electromagnetic form factors (EFFs) is performed within a Dyson-Schwinger equations approach to quantum chromodynamics. These form factors are calculated in the so called rainbow-ladder (RL) truncation, following two different evaluation methods and, subsequently, in a beyond RL truncation that incorporates meson cloud effects. The produced image is quite congruent and indicates that, in the domain of relevance for aµ, the obtained EFFs are practically equivalent, thus yielding the combined estimates of a π ± −box µ = −(15.6 ± 0.5) × 10 −11 and a K ± −box µ = −(0.48 ± 0.04) × 10 −11 , in full agreement with previous results within the DSE formalism and other contemporary estimates.