diff --git a/include/openmc/mesh.h b/include/openmc/mesh.h
index ebfa083d0d..442c0d4ac5 100644
--- a/include/openmc/mesh.h
+++ b/include/openmc/mesh.h
@@ -79,7 +79,7 @@ public:
   virtual xt::xarray<double>
   count_sites(const std::vector<Particle::Bank>& bank, bool* outside) const = 0;
 
-  virtual double get_volume_frac(int bin = -1) = 0;
+  virtual double get_volume_frac(int bin = -1) const = 0;
 
   int id_ {-1};  //!< User-specified ID
   int n_dimension_; //!< Number of dimensions
diff --git a/src/mesh.cpp b/src/mesh.cpp
index 7a70080e92..0e9c321643 100644
--- a/src/mesh.cpp
+++ b/src/mesh.cpp
@@ -1408,7 +1408,7 @@ openmc_extend_meshes(int32_t n, int32_t* index_start, int32_t* index_end)
 {
   if (index_start) *index_start = model::meshes.size();
   for (int i = 0; i < n; ++i) {
-    model::meshes.push_back(std::make_unique<RegularMesh>());
+    model::meshes.push_back(std::move(std::make_unique<RegularMesh>()));
   }
   if (index_end) *index_end = model::meshes.size() - 1;
 
@@ -1780,6 +1780,7 @@ void read_meshes(pugi::xml_node root)
 {
   for (auto node : root.children("mesh")) {
 
+
     std::string mesh_type;
     if (check_for_node(node, "type")) {
       mesh_type = get_node_value(node, "type", true, true);