We present a direct determination of the stellar metallicity in the close pair galaxy NGC 4038 ( D = 20 Mpc ) based on the quantitative analysis of moderate resolution KMOS/VLT spectra of three super star clusters ( SSCs ) . The method adopted in our analysis has been developed and optimised to measure accurate metallicities from atomic lines in the J -band of single red supergiant ( RSG ) or RSG-dominated star clusters . Hence , our metallicity measurements are not affected by the biases and poorly understood systematics inherent to strong line H ii methods which are routinely applied to massive data sets of galaxies . We find [ Z ] = +0.07 \pm 0.03 and compare our measurements to H ii strong line calibrations . Our abundances and literature data suggest the presence of a flat metallicity gradient , which can be explained as redistribution of metal-rich gas following the strong interaction .