We analyze the rate and direction of technological progress of standards subject to declared standard-essential patents (SEP). We observe continuous and discontinuous changes in a sample of 3500 ICT standards. Standards including SEPs change significantly more often than other standards. This difference is particularly pronounced if ownership over patents is concentrated. Furthermore, standards subject to SEPs are characterized by a more continuous pattern of technological progress. While the existence of SEPs is correlated with a significantly higher number of continuous standard upgrades, standards subject to SEPs are much less likely to experience discontinuous standard replacements. In particular, standards are less likely to be replaced if the owners of the SEPs are relatively more specialized on the technological field of the standard.