diff --git a/include/samplers/gaussian_samplers.h b/include/samplers/gaussian_samplers.h
index 607e240fe..6c8b7acf5 100644
--- a/include/samplers/gaussian_samplers.h
+++ b/include/samplers/gaussian_samplers.h
@@ -60,7 +60,7 @@ NT get_max_coord(const NT &l, const NT &u, const NT &a_i) {
 
 // Pick a point from the distribution exp(-a_i||x||^2) on the chord
 template <typename Parameters, typename Point, typename NT>
-void rand_exp_range(Point const &lower, Point const & upper, const NT &a_i, Point &p, Parameters const& var) {
+void rand_exp_range(Point &lower, Point & upper, const NT &a_i, Point &p, Parameters const& var) {
     typedef typename Parameters::RNGType RNGType;
     NT r, r_val, fn;
     const NT tol = 0.00000001;