Disclosed is a method for sealing a joint between a first blade section and a second blade section of a wind turbine blade, a sealing member and a wind turbine blade comprising a sealing member. The sealing member having a first surface and a second surface. The sealing member having a width between a first edge and a second edge. The sealing member being configured for attachment to the first outer shell along the first edge, and for attachment to the second outer shell along the second edge. The sealing member comprising a corrugated section between the first edge and the second edge, the corrugated section comprising one or more valleys and/or ridges extending along a lengthwise direction of the sealing member.