According to the present invention there is provided a wind turbine blade extending in a spanwise direction between a root and a tip, and in a chordwise direction between a leading edge and a trailing edge. The wind turbine blade has a spar cap comprising a plurality of strips of fibrous composite material. Each strip extends in the spanwise direction between a first end and a second end to define a length of the strip, and each strip has a width and a thickness, the width being less than the length, and the thickness being less than the width. Each strip has upper and lower major surfaces defined by the length and width dimensions. Each strip has side surfaces defined by the length and thickness dimensions. The plurality of strips includes a first strip and a second strip. The first strip has a tapered end portion in which the thickness of the first strip decreases towards the first end of the first strip. The tapered end portion defines a tapered end face inclined with respect to the upper and lower major surfaces of the first strip. The first and second strips are bonded together such that the first end of the first strip meets the upper or lower major surface of the second strip to define an interface between the first and second strips. The spar cap further comprises a patch arranged across the interface. The patch comprises a stack of fibrous plies.