How do peoples' attitudes towards immigration change when exposed to dramatic declines in the availability of immigrant labor? Swiss agricultural production relies heavily on foreign labor. However, the pandemic lockdown caused a shortage of foreign seasonal workers in the spring of 2020. We combine fine-grained voting results from referendums on specific immigration-related policy decisions with variation in seasonal worker needs. We establish that municipalities growing spring crops, and therefore facing severe shortages of foreign labor in spring 2020, voted significantly more in favor of immigration in September 2020 compared to otherwise similar municipalities. Further, using text data from open-ended survey questions, we document how this shock popularized a narrative highlighting the role of foreign workers as complements to the local native ones rather than substitutes. We conclude that economic shocks can influence economic narratives and, ultimately, change attitudes toward immigration.