diff --git a/include/openmc/mesh.h b/include/openmc/mesh.h
index d8164a1590..d91d529415 100644
--- a/include/openmc/mesh.h
+++ b/include/openmc/mesh.h
@@ -315,8 +315,19 @@ public:
   void bins_crossed(const Particle* p, std::vector<int>& bins,
                     std::vector<double>& lengths) const;
 
+
   bool intersects(Position& r0, Position r1, int* ijk);
 
+
+private:
+  void
+  intersect_track(const moab::CartVect& start,
+                  const moab::CartVect& dir,
+                  double track_len,
+                  std::vector<moab::EntityHandle>& tris,
+                  std::vector<double>& intersection_dists) const;
+
+public:
   //! Determine which surface bins were crossed by a particle
   //
   //! \param[in] p Particle to check
diff --git a/src/mesh.cpp b/src/mesh.cpp
index ad79b2714c..212b46b21b 100644
--- a/src/mesh.cpp
+++ b/src/mesh.cpp
@@ -1619,6 +1619,27 @@ UnstructuredMesh::build_tree(const moab::Range& all_tets) {
 
 }
 
+void
+UnstructuredMesh::intersect_track(const moab::CartVect& start,
+                                  const moab::CartVect& dir,
+                                  double track_len,
+                                  std::vector<moab::EntityHandle>& tris,
+                                  std::vector<double>& intersection_dists) const {
+
+  moab::ErrorCode rval = kdtree_->ray_intersect_triangles(kdtree_root_,
+                                                          1E-03,
+                                                          dir.array(),
+                                                          start.array(),
+                                                          tris,
+                                                          intersection_dists,
+                                                          0,
+                                                          track_len);
+  if (rval != moab::MB_SUCCESS) {
+    fatal_error("Failed to compute tracklengths on umesh: " + filename_);
+  }
+
+}
+
 void
 UnstructuredMesh::bins_crossed(const Particle* p, std::vector<int>& bins,
                                std::vector<double>& lengths) const {
@@ -1640,10 +1661,7 @@ UnstructuredMesh::bins_crossed(const Particle* p, std::vector<int>& bins,
   std::vector<moab::EntityHandle> tris;
   std::vector<double> intersections;
 
-  rval = kdtree_->ray_intersect_triangles(kdtree_root_, 1E-03, dir.array(), r0.array(), tris, intersections, 0, track_len);
-  if (rval != moab::MB_SUCCESS) {
-    fatal_error("Failed to compute tracklengths on umesh: " + filename_);
-  }
+  intersect_track(r0, dir, track_len, tris, intersections);
 
   bins.clear();
   for (const auto& int_dist : intersections) {