Disclosed is the phosphate salt or a nitrate salt of 4-(R)-6,7-dihydro-5H-pyrrolo[1,2-c]imidazol-5-yl-3-fluoro-benzonitrile in crystalline form, and methods of producing the salts. The salts and salt forms allow for the prophylactic and/or therapeutic treatment of aldosterone synthase and/or aromatase mediated diseases or disorders such as Cushing’s disease.