Computer simulations of the adsorption of hydrocarbons in zeolites are usually performed using rigid zeolite frameworks. This allows for the use of grid interpolation techniques to compute the hydrocarbon-zeolite interaction very efficiently. In this paper, we investigate the influence of the framework flexibility on the adsorption properties of hydrocarbons adsorbed in the zeolite silicalite. We find that at low loading, the influence of the framework flexibility on the heat of adsorption and the Henry coefficient is quite small. However, for molecules such as isobutane and heptane with inflection behavior, the influence at high loading seems to be much larger.