Despite the reversal of gender differences in educational attainment, women continue to be underrepresented in STEM (Science, Technology, Engineering, Mathematics) occupations. Yet comparative studies indicate that the male advantage in STEM fields varies across countries. To understand how these country variations come about, this study analyzes the gender gap in adolescents' STEM expectations. While previous research mainly focused on the role of the cultural environment and the education system, this study contributes to the literature by investigating the opportunity structures of the labor market. We study how employment opportunities in science and technology, the post-industrial restructuring of labor markets in both low- and high-status occupations, and women's success in graduating from STEM fields might explain the gender gap in STEM expectations. Empirically, we analyze 15-year-old pupils' occupational expectations from the OECD's PISA 2015 study linked with macro-level indicators in 35 EU and OECD countries by means of two-step multilevel models. Results indicate that the gender gap in STEM expectations is larger in countries with a more pronounced post-industrial restructuring of the labor market. However, rather than steering girls away from the STEM sector, post-industrial restructuring increases boys' STEM expectations and thus seems to strengthen their gender-typical tasks preferences.