[en] We have measured the moment of inertia of hcp ⁴He crystals from 25 mK to 2 K. With a precision of five parts in 10⁶ we find no evidence for a nonclassical rotational inertia. This indicates that if a supersolid exists, it has a rho/sub s//rho of less than 5 x 10^-6, a transition temperature of less than 25 mK, or a critical velocity of less than 5 μm/sec