The paper deals with a modification of the CAPM, being called the Mayers model, which takes into account the existence of nonmarketable assets. Human capital is the classic example of such assets though we present and discuss some other important examples. This approach, as well as more advanced conditional CAPM, gives a correction to traditional CAPM beta coefficient as a measure of market risk. In this paper we present two attempts to test CAPM with nonmarketable assets. First, we start from analysis of the small size effect of the Russian stock market. We show that in this case the Mayers model gives the possibility of substantial improvement of risk exposure estimate. Second, empirical analysis in the case of human capital shows no impact of the Mayers model in all sectors of the Moscow Stock Exchange other than Innovation.