A level shifting circuit has a pair of assist circuits. The level shifting circuit includes an input point, an output point, a pair of cross-coupled PMOS transistors coupled to the output point, and a pair of NMOS transistors coupled between the input and output points. Each assist circuit includes a pair of PMOS transistors, one responsive to an input applied to the input point, the other responsive to the drain voltage of one of the NMOS transistors. The assist circuits temporarily weaken the cross-coupled PMOS transistors when an input changes from low to high, or from high to low. The assist circuits also transiently boost the output.