The present disclosure is directed to a rotor blade for a turbomachine. The rotor blade includes an airfoil and a tip shroud coupled to the airfoil. The tip shroud defines a core. The tip shroud includes a rib positioned within the core and a radially outer wall. The rib separates a first portion of the core and a second portion of the core. The airfoil, the rib, and the radially outer wall partially define a first cooling passage fluidly isolated from the core.