diff --git a/libsrc/gprim/geomtest3d.hpp b/libsrc/gprim/geomtest3d.hpp
index b26c9b41..954d32e7 100644
--- a/libsrc/gprim/geomtest3d.hpp
+++ b/libsrc/gprim/geomtest3d.hpp
@@ -69,10 +69,10 @@ extern double ComputeCylinderRadius (const Vec3d & n1, const Vec3d & n2,
 				     double h1, double h2);
 
 /// Minimal distance of point p to the line segment [lp1,lp2]
-extern double MinDistLP2 (const Point2d & lp1, const Point2d & lp2, const Point2d & p);
+DLL_HEADER double MinDistLP2 (const Point2d & lp1, const Point2d & lp2, const Point2d & p);
 
 /// Minimal distance of point p to the line segment [lp1,lp2]
-extern double MinDistLP2 (const Point3d & lp1, const Point3d & lp2, const Point3d & p);
+DLL_HEADER double MinDistLP2 (const Point3d & lp1, const Point3d & lp2, const Point3d & p);
 
 /// Minimal distance of point p to the triangle segment [tp1,tp2,pt3]
 DLL_HEADER double MinDistTP2 (const Point3d & tp1, const Point3d & tp2, 
diff --git a/libsrc/meshing/delaunay2d.cpp b/libsrc/meshing/delaunay2d.cpp
index e88434bf..db6bcc71 100644
--- a/libsrc/meshing/delaunay2d.cpp
+++ b/libsrc/meshing/delaunay2d.cpp
@@ -668,6 +668,11 @@ namespace netgen
     for (auto pi : points_range)
       dmesh.AddPoint(pi);
 
+    auto first_new_point = points_range.Next();
+    tempmesh.AddPoint(P3(temp_points[first_new_point]));
+    tempmesh.AddPoint(P3(temp_points[first_new_point+1]));
+    tempmesh.AddPoint(P3(temp_points[first_new_point+2]));
+
     timer_addpoints.Stop();
 
     static Timer taddseg("addseg");
diff --git a/libsrc/meshing/improve2.cpp b/libsrc/meshing/improve2.cpp
index b215bfd7..c46df8a0 100644
--- a/libsrc/meshing/improve2.cpp
+++ b/libsrc/meshing/improve2.cpp
@@ -339,6 +339,9 @@ namespace netgen
             if (swapped[t1])
               return;
 
+            if(mesh[t1].GetNP() != 3)
+              return;
+
             if (multithread.terminate)
               throw NgException ("Meshing stopped");
 
diff --git a/libsrc/meshing/smoothing2.cpp b/libsrc/meshing/smoothing2.cpp
index 11f21cb8..0e6db78a 100644
--- a/libsrc/meshing/smoothing2.cpp
+++ b/libsrc/meshing/smoothing2.cpp
@@ -756,10 +756,17 @@ namespace netgen
       {
         for (auto & se : mesh.SurfaceElements())
           if (se.GetNP() != 3)
-            {
-              mixed = true;
-              break;
-            }
+          {
+              for(auto pi : se.PNums())
+                  if(mesh[pi].Type() == SURFACEPOINT)
+                  {
+                      mixed = true;
+                      break;
+                  }
+              if(mixed)
+                  break;
+          }
+
         const auto & getDofs = [&] (int i)
           {
             return elementsonpoint[i+PointIndex::BASE];