diff --git a/include/zeus/COBBox.hpp b/include/zeus/COBBox.hpp
index 4087359..a89ff8c 100644
--- a/include/zeus/COBBox.hpp
+++ b/include/zeus/COBBox.hpp
@@ -43,7 +43,7 @@ public:
 
     }
 
-    CAABox calculateAABox(const CTransform& transform = CTransform())
+    CAABox calculateAABox(const CTransform& transform = CTransform()) const
     {
         CAABox ret = CAABox::skInvertedBox;