We investigate the decay B-s(0) -> J/psi K+K- for invariant masses of the K+K- pair in the range 1.35 J/psi f(2)'(1525) and measure the relative branching fraction of the decays B-s(0) -> J/psi f(2)'(1525) and B-s(0) -> J/psi phi to be R-f2'/phi = 0.19 +/- 0.05(stat) +/- 0.04(syst).