diff --git a/EGkSurfBezier.h b/EGkSurfBezier.h
index ee3147e..6b41fa3 100644
--- a/EGkSurfBezier.h
+++ b/EGkSurfBezier.h
@@ -96,7 +96,7 @@ class __declspec( novtable) ISurfBezier : public ISurf
       virtual bool IsPlanar( void) const = 0 ;
       virtual bool CreateByFlatContour( const PolyLine& PL) = 0 ;
       virtual bool CreateByRegion( const POLYLINEVECTOR& vPL) = 0 ;
-      virtual bool CreateByExtrusion( const ICurve* pCrv, const Vector3d& vtExtr, bool bDeg3OrDeg2 = false) = 0 ;
+      virtual bool CreateByExtrusion( const ICurve* pCrv, const Vector3d& vtExtr) = 0 ;
       virtual bool CreateByScrewing( const ICurve* pCurve, const Point3d& ptAx, const Vector3d& vtAx, double dAngRotDeg, double dMove) = 0 ;
       virtual bool CreateByPointCurve( const Point3d& pt, const ICurve* pCurve) = 0 ;
       virtual bool CreateByTwoCurves( const ICurve* pCurve1, const ICurve* pCurve2, int nType) = 0 ;