diff --git a/src/Mod/OpenSCAD/OpenSCADTest/app/test_importCSG.py b/src/Mod/OpenSCAD/OpenSCADTest/app/test_importCSG.py
index d7ac8afd48..0fc8083ac1 100644
--- a/src/Mod/OpenSCAD/OpenSCADTest/app/test_importCSG.py
+++ b/src/Mod/OpenSCAD/OpenSCADTest/app/test_importCSG.py
@@ -349,6 +349,7 @@ resize(newsize = [0,0,10], auto = [0,0,0]) {
 }""", "resize_non_uniform_sphere")
         object = doc.ActiveObject
         self.assertTrue (object is not None)
+        object.Shape.tessellate(0.025) # To ensure the bounding box calculation is correct
         self.assertAlmostEqual (object.Shape.BoundBox.XLength, 2*8.5, 1)
         self.assertAlmostEqual (object.Shape.BoundBox.YLength, 2*8.5, 1)
         self.assertAlmostEqual (object.Shape.BoundBox.ZLength, 10.0, 1)
diff --git a/src/Mod/OpenSCAD/importCSG.py b/src/Mod/OpenSCAD/importCSG.py
index 98197cec53..c59dc778ce 100644
--- a/src/Mod/OpenSCAD/importCSG.py
+++ b/src/Mod/OpenSCAD/importCSG.py
@@ -466,23 +466,19 @@ def p_minkowski_action(p):
 def p_resize_action(p):
     '''
     resize_action : resize LPAREN keywordargument_list RPAREN OBRACE block_list EBRACE '''
-    print(p[3])
     new_size = p[3]['newsize']
     auto    = p[3]['auto'] 
-    print(new_size)
-    print(auto)
     p[6][0].recompute()
     if p[6][0].Shape.isNull():
         doc.recompute()
+    p[6][0].Shape.tessellate(0.05)
     old_bbox = p[6][0].Shape.BoundBox
-    print ("Old bounding box: " + str(old_bbox))
     old_size = [old_bbox.XLength, old_bbox.YLength, old_bbox.ZLength]
     for r in range(0,3) :
         if auto[r] == '1' :
            new_size[r] = new_size[0]
         if new_size[r] == '0' :
            new_size[r] = str(old_size[r])
-    print(new_size)
 
     # Calculate a transform matrix from the current bounding box to the new one:
     transform_matrix = FreeCAD.Matrix()
@@ -1314,8 +1310,10 @@ def p_projection_action(p) :
     if printverbose: print('Projection')
 
     doc.recompute()
+    p[6][0].Shape.tessellate(0.05) # Ensure the bounding box calculation is not done with the splines, which can give a bad result
     bbox = p[6][0].Shape.BoundBox
     for shape in p[6]:
+        shape.Shape.tessellate(0.05)
         bbox.add(shape.Shape.BoundBox)
     print (bbox)
     plane = doc.addObject("Part::Plane","xy_plane_used_for_projection")