A rotor blade 40 for a gas turbine engine has an aerofoil portion 42 from a root 48 to a tip 54. In use, combustion gas may leak over the tip 54 from the pressure face 52 to the suction face 50. A gutter 62 extends across the tip 54 to entrain any over tip leakage gap. The floor of the gutter defines an increased depth portion 72 at the exit end of the gutter 62.