What is the impact of technological change on the demand for skills? What about skills specifically related to STEM occupations? To determine this, we match occupational data from the 2006 and 2016 Canadian Censuses with detailed data that associate measures of skill and competencies required to occupy each occupation. We find that the demand for math-related skills has increased over this period, but that the increase is concentrated among STEM and STEM-related occupations. We also find that changes in skill demand are observed within finely defined occupations, rather than through changes in occupational structure.