diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index ccdf78b4..c7852a6d 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -81,11 +81,20 @@ test_win:
   script:
     - pip install pytest-check
     - cd tests\pytest
-    - REM python test_tutorials.py new_results.json
     - cd %NETGEN_BUILD_DIR%\netgen
     - ctest -C Release -V --output-on-failure
     - cd ..
   needs: ["build_win"]
+
+generate_results:
+  <<: *win
+  stage: test
+  script:
+    - pip install pytest-check
+    - cd tests\pytest
+    - python test_tutorials.py new_results.json
+  needs: ["build_win"]
+  when: manual
   artifacts:
     paths:
       - tests/pytest/new_results.json
diff --git a/libsrc/meshing/improve3.cpp b/libsrc/meshing/improve3.cpp
index 1fcb11af..620a650b 100644
--- a/libsrc/meshing/improve3.cpp
+++ b/libsrc/meshing/improve3.cpp
@@ -564,9 +564,6 @@ double MeshOptimize3d :: SplitImproveEdge (Table<ElementIndex,PointIndex> & elem
           Element newel1 = oldel;
           Element newel2 = oldel;
 
-          oldel.Touch();
-          oldel.Delete();
-
           newel1.Touch();
           newel2.Touch();
 
@@ -576,6 +573,12 @@ double MeshOptimize3d :: SplitImproveEdge (Table<ElementIndex,PointIndex> & elem
               if (newel2[l] == pi1) newel2[l] = pinew;
             }
 
+          if( newel1.Volume(mesh.Points()) < 0.0 || newel2.Volume(mesh.Points()) < 0.0)
+            return 0.0;
+
+          oldel.Touch();
+          oldel.Delete();
+
           mesh.AddVolumeElement (newel1);
           mesh.AddVolumeElement (newel2);
         }
diff --git a/tests/pytest/results.json b/tests/pytest/results.json
index 8f58035e..c455838d 100644
--- a/tests/pytest/results.json
+++ b/tests/pytest/results.json
@@ -827,98 +827,6 @@
             "total_badness": 100414.60403
         }
     ],
-    "cylinder.geo": [
-        {
-            "angles_tet": [
-                19.071,
-                144.66
-            ],
-            "angles_trig": [
-                22.881,
-                111.85
-            ],
-            "ne1d": 52,
-            "ne2d": 286,
-            "ne3d": 394,
-            "quality_histogram": "[0, 0, 0, 0, 0, 0, 0, 2, 2, 6, 18, 38, 45, 53, 70, 51, 48, 40, 12, 9]",
-            "total_badness": 562.09628542
-        },
-        {
-            "angles_tet": [
-                22.85,
-                151.98
-            ],
-            "angles_trig": [
-                25.237,
-                118.13
-            ],
-            "ne1d": 24,
-            "ne2d": 66,
-            "ne3d": 69,
-            "quality_histogram": "[0, 0, 0, 0, 0, 0, 1, 1, 3, 3, 3, 5, 0, 4, 2, 2, 9, 26, 3, 7]",
-            "total_badness": 95.643757297
-        },
-        {
-            "angles_tet": [
-                14.788,
-                156.92
-            ],
-            "angles_trig": [
-                11.549,
-                134.56
-            ],
-            "ne1d": 36,
-            "ne2d": 152,
-            "ne3d": 548,
-            "quality_histogram": "[0, 0, 0, 0, 1, 7, 24, 35, 41, 59, 44, 55, 57, 51, 39, 38, 48, 26, 19, 4]",
-            "total_badness": 980.19781779
-        },
-        {
-            "angles_tet": [
-                19.062,
-                144.68
-            ],
-            "angles_trig": [
-                22.836,
-                111.85
-            ],
-            "ne1d": 52,
-            "ne2d": 286,
-            "ne3d": 394,
-            "quality_histogram": "[0, 0, 0, 0, 0, 0, 0, 2, 2, 6, 18, 38, 45, 52, 71, 52, 46, 41, 12, 9]",
-            "total_badness": 562.08196742
-        },
-        {
-            "angles_tet": [
-                23.602,
-                139.69
-            ],
-            "angles_trig": [
-                23.844,
-                118.54
-            ],
-            "ne1d": 76,
-            "ne2d": 636,
-            "ne3d": 1056,
-            "quality_histogram": "[0, 0, 0, 0, 0, 0, 0, 0, 2, 16, 35, 78, 108, 109, 163, 185, 154, 105, 81, 20]",
-            "total_badness": 1453.0463737
-        },
-        {
-            "angles_tet": [
-                24.173,
-                139.41
-            ],
-            "angles_trig": [
-                26.472,
-                120.11
-            ],
-            "ne1d": 124,
-            "ne2d": 1666,
-            "ne3d": 6448,
-            "quality_histogram": "[0, 0, 0, 0, 0, 0, 0, 0, 2, 6, 17, 44, 136, 282, 586, 944, 1320, 1470, 1240, 401]",
-            "total_badness": 7815.6380623
-        }
-    ],
     "cylsphere.geo": [
         {
             "angles_tet": [
@@ -3422,4 +3330,4 @@
             "total_badness": 12938.174838
         }
     ]
-}
+}
\ No newline at end of file