The proton-proton bremsstrahlung is investigated within a coupled-channel model with the Δ degree of freedom. The model is consistent with the NN scattering up to 1 GeV and the γ NΔ vertex determined in the study of pion photoproduction reactions. It is found that the Δ excitation can significantly improve the agreements with the pp → ppγ at E_lab=280 MeV. Predictions at E_lab=550 and 800 MeV are presented for future experimental tests.