  The two-dimensional CGHS model provides an interesting toy-model for the
study of black hole evaporation. For this model, a quantum effective action,
which incorporates Hawking radiation and backreaction, can be explicitly
constructed. In this paper, we study a generalization of this effective action.
In our extended model, it is possible to remove certain curvature singularities
arising for the original theory. We also find that the flux of Hawking
radiation is identical to that encountered in other two-dimensional models.
