Abstract Biostratigraphical re-analysis of palaeobotanical data from the De Lutte-06 well clarifies an earlier controversy regarding the stratigraphical interpretation of this well based on palaeobotanical and palynological analysis. Previous biostratigraphical studies suggested an early Westphalian D age for the major part of the De Lutte formation, with only at the topmost part of the well remnants of presumable but unconfirmed Stephanian deposits. New identifications of palaeobotanical samples illustrate the presence of plant macrofossil assemblages in the De Lutte Formation characteristic for the latest Westphalian D to the Stephanian B-C. These new palaeobotanical insights, therefore, confirm a younger age for the De Lutte Formation and are more in line with the earlier palynological observations from the De Lutte-06 well that suggested that the recovered palynofloras resembled typical Stephanian associations.