Misinformation about the novel coronavirus is a pressing societal challenge. Across two studies, one preregistered, we assess the efficacy of two ‘prebunking’ interventions aimed at improving people’s ability to spot manipulation techniques commonly used in COVID-19 misinformation across three different languages. We find that Go Viral!, a novel five-minute browser game, increases the perceived manipulativeness of misinformation about COVID-19, improves people’s attitudinal certainty in their ability to spot misinformation and reduces self-reported willingness to share misinformation with others. The first two (...) effects remain significant for at least one week after gameplay. We also find that reading real-world infographics from UNESCO improves people’s ability and confidence in spotting COVID-19 misinformation. Limitations and implications for fake news interventions are discussed. (shrink)