An extensive body of literature examines the determinants of pro-European attitudes. Yet, the literature has so far overlooked the potential influence of social desirability bias (SDB): the tendency to report responses in line with what is perceived as broadly acceptable. Prima facie evidence suggests that SDB may play a role in pro-European dispositions because it has already proven relevant in regards to a closely related topic: immigration attitudes. This study, therefore, examines the role of SDB through an (already-conducted) online representative sample in Germany (N=3500) and a combination of experimental and cross-sectional analyses. The experimental section implements a conjoint analysis with an already-validated strategy specifically designed to capture the net influence of SDB. Our experiment presents participants with two imaginary parties and seven dimensions of their platforms. The key dimension concerns support for further concessions of decision-making power from Germany to the EU. The cross-sectional section draws on an already-validated battery of SDB attitudes and structural equation models to assess if SDB has a direct effect on an index of pro-European dispositions. This section also explores if SDB mediates the influence of a high level of education on pro-European dispositions. In line with our expectations, we find that there is a positive correlation between higher social desirability and education levels. However, contrary to our expectation, we find that higher social desirability is associated with lower support for European integration. This surprising finding has important implications for understanding the current social debate about the EU.