diff --git a/CurveComposite.cpp b/CurveComposite.cpp
index 77d709d..68d74e0 100644
--- a/CurveComposite.cpp
+++ b/CurveComposite.cpp
@@ -1600,7 +1600,7 @@ CurveComposite::CopyParamRange( double dUStart, double dUEnd) const
   // eseguo il trim della copia
    if ( ! pCopy->TrimStartEndAtParam( dUStart, dUEnd))
       return nullptr ;
-   return ( ::Release( pCopy)) ;
+   return ( pCopy->m_CrvSmplS.empty() ? nullptr : ::Release( pCopy)) ;
 }
 
 //----------------------------------------------------------------------------