The value of the important triple-Pomeron coupling is estimated by an unorthodox procedure using the known diffractive parton distribution functions. The result is g3P≃0.2gN, where gN is the Pomeron–nucleon coupling. This is in excellent agreement with an independent determination, g3P≃0.2gN, previously obtained by analysing the available data in the triple-Regge region with absorptive effects taken into account.