  The slope of the interstellar reddening line in the J-H vs. H-Ks diagram of
the 2MASS survey in the direction of the North America and Pelican nebulae, the
L935 dust cloud and the Cyg OB2 association is determined. The MK types were
either classified by C. J. Corbally or collected from the literature. The ratio
E(J-H)/E(H-Ks) = 2.0 is obtained by taking the average for the four groups of
spectral classes: O3--B1, B2--B6, B7--B9.5 and red clump giants. The obtained
ratio is larger than the `typical' value, 1.7-1.8.
