Reinig et al.1 briefly explored magmatic CO2 incorporation as the reason for an age offset in one of their carbonized wood samples, but ultimately did not correct for it. Because the subfossil trees were sampled at localities near vents, it seems probable that all of the samples were affected by magmatic CO2 to variable extents. Studies from the USA, New Zealand and Italy have demonstrated that magmatic CO2 incorporation rates into trees are spatiotemporally variable4,6-8 (Fig. 1). ...temporally variable magmatic CO2 fluxes7,8 preceding the LSE may have not only made the radiocarbon dates of the wood samples seem generally older, but also affected the shape of the radiocarbon curve produced by Reinig et al.1 (Fig. 1), thus yielding a spurious correlation when wiggle-matched with the Swiss Late Glacial Master Radiocarbon dataset9,10. ...the observed increase in radiocarbon values immediately before the LSE is surprising. ...we disagree that our radiocarbon (14C) measurements from three subfossil trees killed and buried at different locations by the pyroclastic deposits of the Laacher See eruption (LSE)2 are possibly affected by outgassing magmatic carbon dioxide (CO2).