The present invention provides selective 5-HT7 receptor antagonist compounds of Formula I and their use in the treatment of migraine: where A is —C(H)═ or —N═; m is 0, 1 or 2; R1 is optionally substituted phenyl, optionally substituted pyrazol-4-yl; optionally substituted imidazolyl, optionally substituted pyridyl, or thienyl; R2 is hydrogen or methyl; and R3 and R4 are as defined herein.