A modular wind turbine blade comprising a first blade module and a second blade module, the first blade module comprising a first spar cap portion extending longitudinally in a spanwise direction, and the second blade module comprising a second spar cap portion extending longitudinally in the spanwise direction, the blade modules being configured for connection end-to-end via their respective spar cap portions, the first spar cap portion comprising a plurality of first elongate fingers defining a plurality of first recesses therebetween, the first fingers extending in the spanwise direction and tapering in width towards respective first finger tips; the second spar cap portion comprising a plurality of second elongate fingers defining a plurality of second recesses therebetween, the second fingers extending in the spanwise direction and tapering in width towards respective second finger tips; the first and second finger tips (32a, 32b) being mutually opposed and spaced apart in the spanwise direction such that a connection region is defined between the first and second finger tips; the first and second blade modules (20a, 20b) being connected by at least one connection element comprising a first tapered portion, a second tapered portion, and an intermediate portion between the first and second tapered portions; wherein the first tapered portion is received in a first recess between adjacent first fingers, the second tapered portion is received in a second recess between adjacent second fingers, and the intermediate portion is located in the connection region; characterised in that: the modular wind turbine blade further comprises a U-shaped channel, wherein the first and second elongate fingers (30a, 30b) extend into the U-shaped channel from opposed ends of the channel, and wherein the at least one connection element is substantially encased in adhesive within the U-shaped channel. the first spar cap portion comprising a plurality of first elongate fingers defining a plurality of first recesses therebetween, the first fingers extending in the spanwise direction and tapering in width towards respective first finger tips; the second spar cap portion comprising a plurality of second elongate fingers defining a plurality of second recesses therebetween, the second fingers extending in the spanwise direction and tapering in width towards respective second finger tips; the first and second finger tips (32a, 32b) being mutually opposed and spaced apart in the spanwise direction such that a connection region is defined between the first and second finger tips; the first and second blade modules (20a, 20b) being connected by at least one connection element comprising a first tapered portion, a second tapered portion, and an intermediate portion between the first and second tapered portions; wherein the first tapered portion is received in a first recess between adjacent first fingers, the second tapered portion is received in a second recess between adjacent second fingers, and the intermediate portion is located in the connection region; characterised in that: the modular wind turbine blade further comprises a U-shaped channel, wherein the first and second elongate fingers (30a, 30b) extend into the U-shaped channel from opposed ends of the channel, and wherein the at least one connection element is substantially encased in adhesive within the U-shaped channel.