The 4f(12)5d --> 4f13 emission of Tm2+ is observed for the first time. It consists of a red band emission with vibronic structure. For a parity-allowed 4f-5d transition its decay time is long, viz. 230 mus. In addition intraconfigurational 4f13 line emission is observed. The results are compared to 4f-5d emissions of other divalent lanthanides in SrB4O7.