diff --git a/EGkTriangle3d.h b/EGkTriangle3d.h
index e9f4e3a..c08641c 100644
--- a/EGkTriangle3d.h
+++ b/EGkTriangle3d.h
@@ -455,6 +455,13 @@ CalcNormal( const Point3d& ptP, const Triangle3d& Tria, const TriNormals3d& Tnor
    return vtNorm.Normalize( EPS_ZERO) ;
 }
 
+//----------------------------------------------------------------------------
+inline bool
+CalcNormal( const Point3d& ptP, const Triangle3dEx& Tria, Vector3d& vtNorm)
+{
+   return CalcNormal( ptP, Tria, Tria.GetTriNormals(), vtNorm) ;
+}
+
 //----------------------------------------------------------------------------
 enum TriangleType { OPEN = -1, EXACT = 0, CLOSED = 1 };