The invention relates to a crystalline form of (S)-(2-(6-chloro-7-methyl-1H-benzo[d]imidazol-2-yl)-2-methylpyrrolidin-1-yl)(5-methoxy-2-(2H-1,2,3-triazol-2-yl)phenyl)methanone hydrochloride, processes for the preparation thereof, pharmaceutical compositions containing said crystalline form, and its use as medicament, especially as orexin receptor antagonist.本發明係關於一種(S)-(2-(6-氯-7-甲基-1H-苯并[d]咪唑-2-基)-2-甲基吡咯啶-1-基)(5-甲氧基-2-(2H-1,2,3-三唑-2-基)苯基)甲酮鹽酸鹽之晶形、其製備方法、含有該晶形之醫藥組合物,及其作為藥劑、尤其作為食慾素受體拮抗劑之用途。