The values taken by $\Gamma_0(n)$-modular functions at elliptic points of order 2 for the Fricke group $\Gamma_0(n)^\dagger$ that lie outside $\Gamma_0(n)$ are studied. In the case of a principal modulus (‘Hauptmodul’) for $\Gamma_0(n)$ or $\Gamma_0(n)^\dagger$, the class fields generated by these values are determined.