diff --git a/src/IntPatch/IntPatch_PrmPrmIntersection.cxx b/src/IntPatch/IntPatch_PrmPrmIntersection.cxx
index 8d07c7b2df..1ad7d4b07a 100644
--- a/src/IntPatch/IntPatch_PrmPrmIntersection.cxx
+++ b/src/IntPatch/IntPatch_PrmPrmIntersection.cxx
@@ -2492,6 +2492,9 @@ void IntPatch_PrmPrmIntersection::Perform (const Handle(Adaptor3d_HSurface)& Sur
 
                             Standard_Boolean removeNext = Standard_False;
                             Standard_Boolean removePrev = Standard_False;
+                            //gka
+                            if(cnbV > 1)
+                            {
                             if( ciV == 1)
                             {
                               Standard_Integer dPar = Abs( VPold.Value(ciV) - VPold.Value(ciV+1));
@@ -2539,6 +2542,7 @@ void IntPatch_PrmPrmIntersection::Perform (const Handle(Adaptor3d_HSurface)& Sur
                                     VPold.SetValue(iPo, VPold.Value(iPo) - 1 );
                               } 
                             }
+                            }
 
                             Standard_Integer pI = ciVpar;