diff --git a/dumux/implicit/cellcentered/ccfvelementgeometry.hh b/dumux/implicit/cellcentered/ccfvelementgeometry.hh
index 28ee8bb2b3f8c6f8e3bb6f332c27d97eba383a76..cbf2f7e0007ac903ce0e85a6c52329d0cb26ac12 100644
--- a/dumux/implicit/cellcentered/ccfvelementgeometry.hh
+++ b/dumux/implicit/cellcentered/ccfvelementgeometry.hh
@@ -228,6 +228,14 @@ public:
             }
         }
     }
+
+    /*!
+     * \brief For compatibilty with the box element geometry
+     */
+    int boundaryFaceIndex(const int fIdx, const int vIdxInFace) const
+    {
+        return fIdx;
+    }
 };
 
 }