diff --git a/include/random_walks/uniform_accelerated_billiard_walk.hpp b/include/random_walks/uniform_accelerated_billiard_walk.hpp
index b27dd4b81..30f85e584 100644
--- a/include/random_walks/uniform_accelerated_billiard_walk.hpp
+++ b/include/random_walks/uniform_accelerated_billiard_walk.hpp
@@ -235,8 +235,10 @@ struct AcceleratedBilliardWalk
             NT T;
             const NT dl = 0.995;
             int it;
-            typename Point::Coeff b = P.get_vec();
-            NT* b_data = b.data();
+            if constexpr (std::is_same<MT, Eigen::SparseMatrix<NT, Eigen::RowMajor>>::value) {
+                typename Point::Coeff b = P.get_vec();
+                NT* b_data = b.data();
+            }
 
             for (auto j=0u; j<walk_length; ++j)
             {