diff --git a/include/openmc/mgxs_interface.h b/include/openmc/mgxs_interface.h
index ce0a4a4c7..afd183e87 100644
--- a/include/openmc/mgxs_interface.h
+++ b/include/openmc/mgxs_interface.h
@@ -15,7 +15,7 @@ namespace openmc {
 // Global MGXS data container structure
 //==============================================================================
 
-struct MgxsInterface {
+class MgxsInterface {
 public:
 
   MgxsInterface() = default;