diff --git a/include/openmc/mesh.h b/include/openmc/mesh.h
index 1bac011e6..49d9dd872 100644
--- a/include/openmc/mesh.h
+++ b/include/openmc/mesh.h
@@ -506,7 +506,7 @@ private:
   moab::Range ehs_; //!< Range of tetrahedra EntityHandle's in the mesh
   moab::EntityHandle tetset_; //!< EntitySet containing all tetrahedra
   moab::EntityHandle kdtree_root_; //!< Root of the MOAB KDTree
-  unique_ptr<moab::Interface> mbi_;         //!< MOAB instance
+  std::shared_ptr<moab::Interface> mbi_;    //!< MOAB instance
   unique_ptr<moab::AdaptiveKDTree> kdtree_; //!< MOAB KDTree instance
   vector<moab::Matrix3> baryc_data_;        //!< Barycentric data for tetrahedra
   vector<std::string> tag_names_; //!< Names of score tags added to the mesh
diff --git a/src/mesh.cpp b/src/mesh.cpp
index e81f2c82d..623589115 100644
--- a/src/mesh.cpp
+++ b/src/mesh.cpp
@@ -1621,13 +1621,16 @@ void MOABMesh::initialize() {
 void
 MOABMesh::create_interface()
 {
-  // create MOAB instance
-  mbi_ = make_unique<moab::Core>();
+  if(mbi_ == nullptr){
+    // create MOAB instance
+    mbi_ = std::make_shared<moab::Core>();
+
+    // load unstructured mesh file
+    moab::ErrorCode rval = mbi_->load_file(filename_.c_str());
+    if (rval != moab::MB_SUCCESS) {
+      fatal_error("Failed to load the unstructured mesh file: " + filename_);
+    }
 
-  // load unstructured mesh file
-  moab::ErrorCode rval = mbi_->load_file(filename_.c_str());
-  if (rval != moab::MB_SUCCESS) {
-    fatal_error("Failed to load the unstructured mesh file: " + filename_);
   }
 }