diff --git a/include/openmc/cell.h b/include/openmc/cell.h
index 5f6d33c974..6f9d879413 100644
--- a/include/openmc/cell.h
+++ b/include/openmc/cell.h
@@ -244,14 +244,14 @@ public:
 
   explicit CSGCell(pugi::xml_node cell_node);
 
-  bool contains(Position r, Direction u, int32_t on_surface) const;
+  bool contains(Position r, Direction u, int32_t on_surface) const override;
 
   std::pair<double, int32_t> distance(
-    Position r, Direction u, int32_t on_surface, Particle* p) const;
+    Position r, Direction u, int32_t on_surface, Particle* p) const override;
 
   void to_hdf5_inner(hid_t group_id) const override;
 
-  BoundingBox bounding_box() const;
+  BoundingBox bounding_box() const override;
 
 protected:
   bool contains_simple(Position r, Direction u, int32_t on_surface) const;