diff --git a/include/openmc/mesh.h b/include/openmc/mesh.h
index 8fdf62ecb6..e6f5ce98b9 100644
--- a/include/openmc/mesh.h
+++ b/include/openmc/mesh.h
@@ -415,7 +415,7 @@ public:
   void to_hdf5(hid_t group) const override;
 
   array<vector<double>, 3> grid_;
-  vector<double> centre_;
+  array<double, 3> centre_;
 
   int set_grid();