Modernization theorists’ ‘rising tide hypothesis’ predicted the continuous spread of egalitarian gender ideologies across the globe. We revisit this assumption by studying reunified Germany, a country that did not follow a strict modernization pathway. The socialist German Democratic Republic (GDR) actively fostered female employment and systematically promoted egalitarian ideologies before reunification with West Germany and the resulting incorporation into a conservative welfare state and market economy. Based on nationally representative, pooled cross-sectional data from the German General Social Survey (ALLBUS) from 1991 to 2016, we apply variance function regression to examine the impact of German reunification—akin to a natural experiment—on the average levels and dispersion of gender ideology. The results show: (i) East German cohorts socialized after reunification hold less egalitarian ideologies than cohorts socialized in the GDR, disrupting the rising tide. (ii) East German cohorts hold more egalitarian ideologies than West German cohorts, but the East-West gap is less pronounced for post-reunification cohorts. (iii) Cohorts in East Germany show higher conformity with gender ideology than their counterparts in West Germany; yet conformity did not change after reunification. (iv) Younger cohorts in West Germany show higher conformity with gender ideology than older cohorts.