diff --git a/OffsetCurve.cpp b/OffsetCurve.cpp
index 106d22c..17de301 100644
--- a/OffsetCurve.cpp
+++ b/OffsetCurve.cpp
@@ -187,7 +187,7 @@ OffsetCurve::Make( const ICurve* pCrv, double dDist, int nType)
       if ( ! ccCopy.StraightArcsToLines( 2 * EPS_SMALL, ANG_CEN_MAX))
          return false ;
      // unisco parti allineate
-      if ( ! ccCopy.MergeCurves( m_dLinTol, ANG_TOL_STD_DEG, bClosed))
+      if ( ! ccCopy.MergeCurves( m_dLinTol, ANG_TOL_STD_DEG, bClosed, true))
          return false ;
 
      // verifico se il punto iniziale è stato modificato