Repro in the playground : https://yak.js.org/playground?q=H4sIAMyYWmgCA1VRvWoDMQzW7KcQB4VkSO1Ct7tmyd6pULqdm5himlwO1y0HJe3WJkP2kCV5Fj1Z5PuLz2ChT5a%2BT5IVaKAzG4N8BND%2Fk%2FVLA7S9lUCnJBUClkB7%2BMFvoL%2BRCGnZzBTeuGkNGC7sV%2BsiAu16f6WrCdAB75Uqq7QN55vW6cqZwK7eeoD44eYPCdgkCsWsMfOdUjcd8YAcUUb89UzTR1P5yYt%2Bz2SDr%2B%2FPTpelcX1JJnmkBmTyOuw4FRvexzwPW6HjbF14bQvj4JfT8xA1Vbl2ntvdt5Sj8WBvXUUv1HTigx20xbJxbq0cvurE5pXVNXzyXVwAi7wfh78BAAA%3D If you explore the markup, you see that the `div` corresponding to `Container` does not get a `class`. This is an issue because even if `Container` is not exported, it might be used as a selector in the same file.