diff --git a/EGkSurfBezier.h b/EGkSurfBezier.h
index c28a2b0..cafefe3 100644
--- a/EGkSurfBezier.h
+++ b/EGkSurfBezier.h
@@ -79,7 +79,7 @@ class __declspec( novtable) ISurfBezier : public ISurf
       virtual bool GetControlCurveOnV( int nIndU, PolyLine& plCtrlV) const = 0 ;
       virtual const ISurfTriMesh* GetAuxSurf( void) const = 0 ;
       virtual const ISurfTriMesh* GetAuxSurfRefined( void) const = 0 ;
-      virtual ISurfTriMesh* GetApproxSurf( double dTol, double dSideMin = 100 * EPS_SMALL) const = 0 ;
+      virtual ISurfTriMesh* GetApproxSurf( double dTol, double dSideMin = 100 * EPS_SMALL, bool bUpdateEdges = false) const = 0 ;
       virtual bool GetLeaves ( std::vector<std::tuple<int, Point3d, Point3d>>& vLeaves) const = 0 ;
       virtual bool GetTriangles2D( std::vector<std::tuple<int,Point3d, Point3d, Point3d>>& vTria2D) const = 0 ;
       virtual bool UnprojectPointFromStm( int nT, const Point3d& ptI, Point3d& ptSP, int nIL) const = 0 ;