It is known that the anomalous Chern-Simons (CS) coupling of Op-plane is not consistent with the T-duality transformations. Compatibility of this coupling with the T-duality requires the inclusion of couplings involving one R-R field strength. In this paper we find such couplings at order α'2. By requiring the R-R and NS-NS gauge invariances, we first find all independent couplings at order α'2. There are 1, 6, 28, 20, 19, 2 couplings corresponding to the R-R field strengths F(p-4), F(p-2), F(p), F(p+2), F(p+4) and F(p+6), respectively. We then impose the T-duality constraint on these couplings and on the CS coupling C(p-3) ∧ R ∧ R at order α'2 to fix their corresponding coefficients. The T-duality constraint fixes all coefficients in terms of the CS coefficient. They are fully consistent with the partial couplings that have been already found in the literature by the S-matrix method.