diff --git a/include/htool/hmatrix/tree_builder/tree_builder.hpp b/include/htool/hmatrix/tree_builder/tree_builder.hpp
index b666d872..3a8a796b 100644
--- a/include/htool/hmatrix/tree_builder/tree_builder.hpp
+++ b/include/htool/hmatrix/tree_builder/tree_builder.hpp
@@ -108,15 +108,15 @@ class HMatrixTreeBuilder {
 
     void set_symmetry_for_leaves(HMatrixType &hmatrix) const {
         if (m_symmetry_type != 'N') {
-            postorder_tree_traversal(hmatrix, [this](HMatrixType &hmatrix) {
-                if (hmatrix.is_leaf() and hmatrix.get_symmetry() != 'N') {
-                    hmatrix.set_symmetry_for_leaves(m_symmetry_type);
-                    hmatrix.set_UPLO_for_leaves(m_UPLO_type);
-                } else if (!hmatrix.is_leaf()) {
-                    for (auto &child : hmatrix.get_children()) {
+            postorder_tree_traversal(hmatrix, [this](HMatrixType &current_hmatrix) {
+                if (current_hmatrix.is_leaf() and current_hmatrix.get_symmetry() != 'N') {
+                    current_hmatrix.set_symmetry_for_leaves(m_symmetry_type);
+                    current_hmatrix.set_UPLO_for_leaves(m_UPLO_type);
+                } else if (!current_hmatrix.is_leaf()) {
+                    for (auto &child : current_hmatrix.get_children()) {
                         if (child->get_symmetry() != 'N') {
-                            hmatrix.set_symmetry_for_leaves(m_symmetry_type);
-                            hmatrix.set_UPLO_for_leaves(m_UPLO_type);
+                            current_hmatrix.set_symmetry_for_leaves(m_symmetry_type);
+                            current_hmatrix.set_UPLO_for_leaves(m_UPLO_type);
                         }
                     }
                 }