In their attempts to implement universal health coverage (UHC), different developing countries encounter different types of obstacles. In Tunisia, major challenges include a widespread informal sector and protestors’ general discontent with rising economic insecurity and inequality, the rollback of the state and public welfare. We apply a contingent valuation survey to a non-healthcare-covered Tunisian sample vis-à-vis joining and paying for a health insurance scheme. We pay attention to the nature of the willingness- to-pay (WTP) values obtained, distinguishing genuine null from protest values. The latter may reflect not only protesters’ beliefs regarding the survey, but also their lack of trust in government’s commitment to ensuring the provision of quality healthcare. We use alternative econometric modeling strategies to account and correct for selection issues arising from protest answers. Our results support the presence of self- selection and, by predicting protesters’ WTP, allow the “true” sample mean WTP to be computed. This appears to be about 14% higher than the elicited mean WTP. The WTP of the poorest non-covered respondents represents about one and a half times the current contributions of the poorest formal sector enrollees, suggesting that voluntary affiliation to the formal health insurance scheme could be a step towards achieving UHC. Overall, we highlight the importance of taking into account protest positions for the evaluation of progress towards UHC.