PWe have found that in some cases, the algorithm from the OpenBabel chemistry toolkit (used by many other software, including Smina) results in incorrect dearomatization. In figures 2a and 2b one can see that OpenBabel has created alternating double bonds in the central ring, which cannot be aromatic because it contains a carbon with sp3 hybridisation. These carbons with three single bonds are circled in red. Because of this error, OpenBabel added extra hydrogens to complete the heavy atom valences. On the other hand, the algorithm of the Indigo package dearomatised the rings correctly, all the atoms of the sp2 ring are hybridised, there are no extra hydrogens.