We introduce a method for the determination of highly accurate estimates of the electronic interaction energies in uncharged hydrogen-bonded clusters, using basis set convergence patterns (=BSCP) of the aug-cc-pVxZ series of basis sets at MP2(FC) level of theory. The method is characterized by its robustness toward systematic deficiencies of MP2(FC)/aug-cc-pVxZ description of hydrogen bonds. The achieved reliability is due to a one parameter scaling ansatz that transforms the disadvantages of the basis set superposition error into precious information. The method is applied to the trimer of hydrogen fluoride and the trimer of water which were both fully geometry optimized up to MP2(FC)/aug-cc-pVQZ level of theory. The electronic interaction energy is predicted to be -15.05 kcal/mol for the trimer of hydrogen fluoride and -15.91 kcal/mol for the trimer of water.