In a recent letter, Govaert et al. examined the relationship between strain hardening modulus G, and flow stress all H, for five different glassy polymers. In each case, results for G, at different strain rates or different temperatures were linearly related to the flow stress. They suggested that this linear relation was inconsistent with simulations. Data from previous publications and new results are presented to show that simulations also yield a linear relation between modulus and flow stress. Possible explanations for the change in the ratio of modulus to flow stress with temperature and strain rate are discussed. (C) 2009 Wiley Periodicals. Inc. J Polym Sci Part B: Polym Phys 47: 1406-1411,2009