A gas turbine engine blade comprises a dovetail, a shank extending from the dovetail, an airfoil, and a platform between the shank and the airfoil. The platform comprises a side wall extending between an upstream side and a downstream side of the platform. A first pin channel extends from the upstream side of the sidewall and a second pin channel, co-axial with the first pin channel, extends from the downstream side of the sidewall. The first channel includes a radial notch at the upstream longitudinal end of the first pin channel.