We report the scintillation properties of BaAl4O7:Eu(2+), a transparent polycrystalline ceramic prepared by full and congruent crystallization of glass. We show that a small deviation from the stoichiometric composition as well as thermal treatment duration play a crucial role in the formation of charge carrier traps, leading to a strong influence on the scintillation yield. We demonstrate that when the traps are not entirely removed, X-ray irradiation allows them to be permanently filled in order to significantly enhance the scintillation output. Finally, the best sample obtained demonstrates performances able to compete with a commercially available scintillating material, CsI:Tl.