In crystalline polyoxymethylene, a system with tightly coupled protons, it is shown experimentally that the averaging of the dipolar local field of protons by multipulse proton homonuclear decoupling leads to a decrease in the spin-spin contribution to the I3C rotating frame relaxation rate.KEY WORDS 13C T,, experiments Attenuation of spin-spin effects Multipulse proton homonuclear decoupling