Responding to harmful content on social media, calls for regulations are coming up to break down the black boxes of social media platforms in handling misinformation. Examples are requiring cooperations with fact-checkers or the government stepping in. So far, there is a lack of knowledge about predictors of policy attitudes in the context of misinformation besides attitudes toward and perceptions of censorship. Using a two-wave panel study in Germany at the beginning of the COVID-19 pandemic and 8 months in, we examine the role of perceived misinformation exposure, perceived harm of misinformation, and trust in institutions involved in regulating misinformation on public support for misinformation regulation. Results show that trust in media and democracy increases policy support over time. Furthermore, perceived exposure to misinformation does not influence policy attitudes, but perceived harm of misinformation does. We discuss the implications for regulating misinformation in light of our findings.