diff --git a/EXE_GeoInters.cpp b/EXE_GeoInters.cpp
index 65bb8c0..2c2d680 100644
--- a/EXE_GeoInters.cpp
+++ b/EXE_GeoInters.cpp
@@ -1032,6 +1032,9 @@ MyCurveCurveInters( const int nId1, const int nId2, const int nDestGrpId, int& n
    CurveLocal Crv1Loc( pGeomDB, nId1, frDest) ;
    CurveLocal Crv2Loc( pGeomDB, nId2, frDest) ;
 
+   if( Crv1Loc.Get() == nullptr  ||  Crv2Loc.Get() == nullptr)
+      return GDB_ID_NULL ;
+
   // intersezione fra le curve nel piano XY locale
    IntersCurveCurve intCC( *Crv1Loc, *Crv2Loc, true) ;
    int nInters = 0 ;