The present invention relates to crystalline forms of N-[1-(5-cyano-pyridin-2-ylmethyl)-1H- pyrazol-3-yl]-2-[4-(1-trifluoromethyl-cyclopropyl)-phenyl]-acetamide, pharmaceutical compositions comprising said crystalline forms and their use as T-type calcium channel blockers in the treatment or prevention of diseases or disorders where T-type calcium channels are involved.