Let X$X$,Y $Y$ be a smooth projective varieties, say over the complex numbers, both acted upon by a connected linear group G$G$. Let f:X-->Y$f\colon X\to Y$ be an equivariant rational map. Let Z$Z$ be a smooth G$G$-subvariety sitting in the indeterminacy locus of f$f$. Let X'$X'$ be the blowup of Z$Z$ in X$X$. Wish a reference to show (1) the action of G$G$ extends to X'$X'$, and (2) the rational map f:X'-->Y$f\colon X'\to Y$ induced by f$f$ is equivariant.