Aflatoxin contamination in food poses severe health risks in many low- and middle-income countries (LMICs), yet many consumers are unaware of their exposure. Moreover, most food markets in these countries are not regulated for food safety and lack credible mechanisms to signal food safety. This study investigates how market-specific exposure information influences consumers' beliefs about their perceived health risk of and exposure to aflatoxin contamination, and willingness to pay (WTP) for tested, certified, and untested maize flour. Based on test results from 150 maize flour samples taken at five informal markets, we generated market-specific exposure to aflatoxin contamination. Using an incentive-compatible discrete choice experiment (DCE) with a random information treatment, we estimated WTP among 370 consumers in Northern Nigeria. The findings reveal that tailored, market-specific information resulted in the most significant updates of belief about exposure to unsafe food, large premiums for tested and certified maize flour, and the largest discount for untested maize flour. Heterogeneity analysis shows that belief updating significantly explains the discount. Findings underscore the potential of market-specific information to mitigate consumer exposure to food safety risks, promote safer food markets, and inform food safety policies in LMICs.