diff --git a/libsrc/interface/nginterface.cpp b/libsrc/interface/nginterface.cpp
index cf3c580e..6ceeed96 100644
--- a/libsrc/interface/nginterface.cpp
+++ b/libsrc/interface/nginterface.cpp
@@ -1749,12 +1749,12 @@ int Ng_GetParentElement (int ei)
   if (mesh->GetDimension() == 3)
     {
       if (ei <= mesh->mlparentelement.Size())
-	return mesh->mlparentelement.Get(ei);
+	return mesh->mlparentelement[ei-1]+1;
     }
   else
     {
       if (ei <= mesh->mlparentsurfaceelement.Size())
-	return mesh->mlparentsurfaceelement.Get(ei);
+	return mesh->mlparentsurfaceelement[ei-1]+1;
     }
   return 0;
 }
@@ -1765,7 +1765,7 @@ int Ng_GetParentSElement (int ei)
   if (mesh->GetDimension() == 3)
     {
       if (ei <= mesh->mlparentsurfaceelement.Size())
-	return mesh->mlparentsurfaceelement.Get(ei);
+	return mesh->mlparentsurfaceelement[ei-1]+1;
     }
   else
     {
diff --git a/libsrc/interface/nginterface_v2.cpp b/libsrc/interface/nginterface_v2.cpp
index 1e3e7af8..782a3381 100644
--- a/libsrc/interface/nginterface_v2.cpp
+++ b/libsrc/interface/nginterface_v2.cpp
@@ -725,34 +725,32 @@ namespace netgen
   
   int Ngx_Mesh :: GetParentElement (int ei) const
   {
-      ei++;
-      if (mesh->GetDimension() == 3)
+    if (mesh->GetDimension() == 3)
       {
-          if (ei <= mesh->mlparentelement.Size())
-              return mesh->mlparentelement.Get(ei)-1;
+        if (ei < mesh->mlparentelement.Size())
+          return mesh->mlparentelement[ei];
       }
-      else
+    else
       {
-          if (ei <= mesh->mlparentsurfaceelement.Size())
-              return mesh->mlparentsurfaceelement.Get(ei)-1;
+        if (ei < mesh->mlparentsurfaceelement.Size())
+          return mesh->mlparentsurfaceelement[ei];
       }
-      return -1;
+    return -1;
   }
 
 
   int Ngx_Mesh :: GetParentSElement (int ei) const
   {
-      ei++;
-      if (mesh->GetDimension() == 3)
+    if (mesh->GetDimension() == 3)
       {
-          if (ei <= mesh->mlparentsurfaceelement.Size())
-              return mesh->mlparentsurfaceelement.Get(ei)-1;
+        if (ei < mesh->mlparentsurfaceelement.Size())
+          return mesh->mlparentsurfaceelement[ei];
       }
-      else
+    else
       {
-          return -1;
+        return -1;
       }
-      return -1;
+    return -1;
   }
 
   int Ngx_Mesh :: GetNIdentifications () const
diff --git a/libsrc/meshing/bisect.cpp b/libsrc/meshing/bisect.cpp
index d8016b6e..b33787e5 100644
--- a/libsrc/meshing/bisect.cpp
+++ b/libsrc/meshing/bisect.cpp
@@ -2203,11 +2203,14 @@ namespace netgen
 
 
     mesh.mlparentelement.SetSize(ne);
-    for (int i = 1; i <= ne; i++)
-      mesh.mlparentelement.Elem(i) = 0;
+    // for (int i = 1; i <= ne; i++)
+    // mesh.mlparentelement.Elem(i) = 0;
+    mesh.mlparentelement = ElementIndex::INVALID;
+    
     mesh.mlparentsurfaceelement.SetSize(nse);
-    for (int i = 1; i <= nse; i++)
-      mesh.mlparentsurfaceelement.Elem(i) = 0;
+    // for (int i = 1; i <= nse; i++)
+    // mesh.mlparentsurfaceelement.Elem(i) = 0;
+    mesh.mlparentsurfaceelement = SurfaceElementIndex::INVALID;    
   
     if (printmessage_importance>0)
     {
@@ -3361,7 +3364,7 @@ namespace netgen
 
 		  mtets[ei] = newtet1;
 		  mtets.Append (newtet2);
-		  mesh.mlparentelement.Append (ei-IndexBASE<ElementIndex>()+1);
+		  mesh.mlparentelement.Append (ei);
 		}
             NgProfiler::StopTimer (timer_bisecttet);
             (*opt.tracer)("bisecttet", true);            
@@ -3508,7 +3511,7 @@ namespace netgen
 		
 		  mtris[i] = newtri1;
 		  mtris.Append (newtri2);
-		  mesh.mlparentsurfaceelement.Append (i+1);
+		  mesh.mlparentsurfaceelement.Append (i);
 		}
 
             NgProfiler::StopTimer (timer_bisecttrig);
diff --git a/libsrc/meshing/meshclass.hpp b/libsrc/meshing/meshclass.hpp
index 4e05dbf2..60fb764f 100644
--- a/libsrc/meshing/meshclass.hpp
+++ b/libsrc/meshing/meshclass.hpp
@@ -224,9 +224,9 @@ namespace netgen
     /// refinement hierarchy
     Array<PointIndices<2>,PointIndex> mlbetweennodes;
     /// parent element of volume element
-    NgArray<int> mlparentelement;
+    Array<ElementIndex, ElementIndex> mlparentelement;
     /// parent element of surface element
-    NgArray<int> mlparentsurfaceelement;
+    Array<SurfaceElementIndex, SurfaceElementIndex> mlparentsurfaceelement;
 
 
 
diff --git a/libsrc/meshing/parallelmesh.cpp b/libsrc/meshing/parallelmesh.cpp
index 7745f33a..29b76dbe 100644
--- a/libsrc/meshing/parallelmesh.cpp
+++ b/libsrc/meshing/parallelmesh.cpp
@@ -959,8 +959,8 @@ namespace netgen
     self.opensegments = NgArray<Segment>(0);
     self.numvertices = 0;
     self.mlbetweennodes = Array<PointIndices<2>,PointIndex> (0);
-    self.mlparentelement = NgArray<int>(0);
-    self.mlparentsurfaceelement = NgArray<int>(0);
+    self.mlparentelement = Array<ElementIndex, ElementIndex>(0);
+    self.mlparentsurfaceelement = Array<SurfaceElementIndex, SurfaceElementIndex>(0);
     self.curvedelems = make_unique<CurvedElements> (self);
     self.clusters = make_unique<AnisotropicClusters> (self);
     self.ident = make_unique<Identifications> (self);
diff --git a/libsrc/meshing/python_mesh.cpp b/libsrc/meshing/python_mesh.cpp
index c9c95002..102d8b55 100644
--- a/libsrc/meshing/python_mesh.cpp
+++ b/libsrc/meshing/python_mesh.cpp
@@ -961,11 +961,13 @@ DLL_HEADER void ExportNetgenMeshing(py::module &m)
            );
       })
     .def_property_readonly("parentelements", [](Mesh & self) {
-      return FlatArray<int>(self.mlparentelement.Size(), &self.mlparentelement[0]);
+      // return FlatArray<int>(self.mlparentelement.Size(), &self.mlparentelement[0]);
+      return FlatArray(self.mlparentelement);
     }, py::keep_alive<0,1>())
     .def_property_readonly("parentsurfaceelements", [](Mesh & self) {
-      return FlatArray<int>(self.mlparentsurfaceelement.Size(),
-                            &self.mlparentsurfaceelement[0]);
+      // return FlatArray<int>(self.mlparentsurfaceelement.Size(),
+      // &self.mlparentsurfaceelement[0]);
+      return FlatArray(self.mlparentsurfaceelement);      
     }, py::keep_alive<0,1>())
     .def_property_readonly("macromesh", [](Mesh & self) {
       auto coarsemesh = make_shared<Mesh>();