The present article investigates case usage with the verb bojat’sja ‘be scared’ in Russian. Many verbs with -sja never combine with objects in the accusative case. The verb bojat’sja historically was among them, but this verb is undergoing a shift and is currently used with both genitive and accusative objects. This study examines the parameters that motivate this change. Using data from the Russian National Corpus and an experimental study, this article shows that the accusative case is more likely to appear when the object is individuated. It is furthermore demonstrated that the use of accusative objects depends on register: Less restricted registers, such as newspaper texts and answers in the experiment, show higher use of accusative objects.