Inhibitors of HCV replication of formula (I), and the N-oxides, salts, and stereoisomers thereof, wherein each dashed line represents an optional double bond; X is Ν, CH and where X bears a double bond it is C; R1a and R1b are hydrogen, C3-7cycloalkyl, aryl, Het, C1-6alkoxy, C1-6alkyl optionally substituted with halo, C1-6alkoxy, cyano, polyhaloC11-6alkoxy, C3-7cycloalkyl, aryl, or with Het; or R1a and R1b together with the nitrogen to which they are attached form a 4 to 6 membered heterocyclic ring which may be optionally substituted; L is a direct bond, -O- , -O-C1-4alkanediyl-, -O-CO-, -O-C(=O)-ΝR5a - or -O -C(=O)-NR5a-C1-4alkanediyl-; R2 is hydrogen, and where X is C or CH, R2 may also be C1-6alkyl; R3 is hydrogen, C1-6alkyl, C1-6alkoxyC1-6alkyl, C3-7cycloalkyl, amino, mono- or diC1-6alkylamino; R4 is aryl or a saturated, a partially unsaturated or completely unsaturated 5 or 6 membered monocyclic or 9 to 12 membered bicyclic heterocyclic ring system wherein said ring system contains one nitrogen, and optionally one to three additional heteroatoms selected from O, S and N, and wherein the remaining ring members are carbon atoms; wherein said ring system may be optionally substituted; n is 3, 4, 5, or 6; p is 1 or 2; aryl is phenyl, naphthyl, indanyl, or 1,2,3,4-tetrahydronaphthyl, each of which may be optionally substituted with one, two or three substituents; and Het is a 5 or 6 membered saturated, partially unsaturated or completely unsaturated heterocyclic ring containing 1 to 4 heteroatoms selected from N, O and S , being optionally condensed with a benzene ring, and wherein Het may be optionally substituted with one, two or three substituents; pharmaceutical compositions containing compounds (I) and processes for preparing compounds (I).