The invention relates to a liquid-crystalline medium, characterised in that it comprises one or more compounds of the formula IA, and one or more compounds of the formula IB, in which RA, RB, XA, XB and Y1-13 have the meanings indicated in Claim 1, and to the use thereof for electro-optical purposes, in particular for shutter glasses, 3D applications, in TN, PS-TN, STN, TN-TFT, OCB, IPS, PS-IPS, FFS, PS-FFS and PS-VA-IPS displays.