Interlocking roof tile, having a head portion, a foot portion opposite the head portion and two opposing side portions (4, 5), wherein the head portion is formed on the underside of the interlocking roof tile with a suspension lug for mounting on a roof batten, wherein an L-shaped water seam region is formed on the upper side of the interlocking roof tile, having a head water seam region in the head portion and a side water seam region in the first side portion, wherein an L-shaped cover seam region is formed on the underside of the interlocking roof tile, having a foot cover seam region in the foot portion and a side cover seam region in the second side portion, wherein a central field is formed between the water seam region and the cover seam region, wherein the water seam region and the cover seam region are formed in such a way that, in the state laid as roof cladding, with adjacent interlocking roof tiles, the cover seam region of the one interlocking roof tile overlaps with the water seam region of the other interlocking roof tile, wherein the foot cover seam region is formed with three cover seam webs and two cover seam grooves, and wherein the side cover seam region is formed with two cover seam webs and one cover seam groove, characterised in that the head water seam region and the side water seam region are each formed with four water seam webs and three water seam grooves, and wherein it is provided that a) the head water seam region and the foot cover seam region are formed in such a way that, in the state laid as roof cladding, with interlocking roof tiles lying one above the other, no cover seam web of the foot cover seam region of the interlocking roof tile lying above it engages in the third water seam groove, when seen in the flow direction, of the head water seam region of the interlocking roof tile lying below, and the head water seam region and the foot cover seam region are formed in such a way that, in the state laid as roof cladding, with interlocking roof tiles lying one above the other, the third cover seam web, when seen in the flow direction, of the foot cover seam region abuts on the fourth water seam web, when seen in the flow direction, of the head water seam region of the interlocking roof tile lying below, and/or b) the side water seam region and the side cover seam region are formed in such a way that, in the state laid as roof cladding, with adjacent interlocking roof tiles, a cover seam web of the side cover seam region of the interlocking roof tile lying above it each engages in the right and left water seam grooves, when seen perpendicularly to the flow direction, of the side water seam region of the interlocking roof tile lying below, and the side water seam region and the side cover seam region are formed in such a way that, in the state laid as roof cladding, with adjacent interlocking roof tiles, no cover seam web of the side cover seam region of the interlocking roof tile lying above it engages in the central water seam groove of the side water seam region of the interlocking roof tile lying below. a) the head water seam region and the foot cover seam region are formed in such a way that, in the state laid as roof cladding, with interlocking roof tiles lying one above the other, no cover seam web of the foot cover seam region of the interlocking roof tile lying above it engages in the third water seam groove, when seen in the flow direction, of the head water seam region of the interlocking roof tile lying below, and the head water seam region and the foot cover seam region are formed in such a way that, in the state laid as roof cladding, with interlocking roof tiles lying one above the other, the third cover seam web, when seen in the flow direction, of the foot cover seam region abuts on the fourth water seam web, when seen in the flow direction, of the head water seam region of the interlocking roof tile lying below, and/or b) the side water seam region and the side cover seam region are formed in such a way that, in the state laid as roof cladding, with adjacent interlocking roof tiles, a cover seam web of the side cover seam region of the interlocking roof tile lying above it each engages in the right and left water seam grooves, when seen perpendicularly to the flow direction, of the side water seam region of the interlocking roof tile lying below, and