diff --git a/InvenTree/InvenTree/models.py b/InvenTree/InvenTree/models.py
index 38539d0118..d5259b2acc 100644
--- a/InvenTree/InvenTree/models.py
+++ b/InvenTree/InvenTree/models.py
@@ -6,7 +6,6 @@ from __future__ import unicode_literals
 
 from django.db import models
 from django.contrib.contenttypes.models import ContentType
-from rest_framework.exceptions import ValidationError
 
 from django.db.models.signals import pre_delete
 from django.dispatch import receiver
@@ -134,32 +133,6 @@ class InvenTreeTree(MPTTModel):
         """
         return '/'.join([item.name for item in self.path])
 
-    def clean(self):
-        """ Custom cleaning
-
-        Parent:
-        Setting the parent of an item to its own child results in an infinite loop.
-        The parent of an item cannot be set to:
-            a) Its own ID
-            b) The ID of any child items that exist underneath it
-
-        Name:
-        Tree node names are limited to a reduced character set
-        """
-
-        super().clean()
-
-        # Parent cannot be set to same ID (this would cause looping)
-        try:
-            if self.parent.id == self.id:
-                raise ValidationError("Category cannot set itself as parent")
-        except:
-            pass
-
-        # Ensure that the new parent is not already a child
-        if self.pk is not None and self.id in self.getUniqueChildren(include_self=False):
-            raise ValidationError("Category cannot set a child as parent")
-
     def __str__(self):
         """ String representation of a category is the full path to that category """
 
diff --git a/InvenTree/InvenTree/tests.py b/InvenTree/InvenTree/tests.py
index 4e238a6c80..2511cf4318 100644
--- a/InvenTree/InvenTree/tests.py
+++ b/InvenTree/InvenTree/tests.py
@@ -5,6 +5,10 @@ from django.core.exceptions import ValidationError
 from .validators import validate_overage, validate_part_name
 from . import helpers
 
+from mptt.exceptions import InvalidMove
+
+from stock.models import StockLocation
+
 
 class ValidatorTest(TestCase):
 
@@ -103,6 +107,54 @@ class TestDownloadFile(TestCase):
         helpers.DownloadFile(bytes("hello world".encode("utf8")), "out.bin")
 
 
+class TestMPTT(TestCase):
+    """ Tests for the MPTT tree models """
+
+    fixtures = [
+        'location',
+    ]
+
+    def setUp(self):
+        super().setUp()
+
+        StockLocation.objects.rebuild()
+
+    def test_self_as_parent(self):
+        """ Test that we cannot set self as parent """
+
+        loc = StockLocation.objects.get(pk=4)
+        loc.parent = loc
+
+        with self.assertRaises(InvalidMove):
+            loc.save()
+
+    def test_child_as_parent(self):
+        """ Test that we cannot set a child as parent """
+
+        parent = StockLocation.objects.get(pk=4)
+        child = StockLocation.objects.get(pk=5)
+
+        parent.parent = child
+        
+        with self.assertRaises(InvalidMove):
+            parent.save()
+
+    def test_move(self):
+        """ Move an item to a different tree """
+
+        drawer = StockLocation.objects.get(name='Drawer_1')
+
+        # Record the tree ID
+        tree = drawer.tree_id
+
+        home = StockLocation.objects.get(name='Home')
+
+        drawer.parent = home
+        drawer.save()
+
+        self.assertNotEqual(tree, drawer.tree_id)
+        
+
 class TestSerialNumberExtraction(TestCase):
     """ Tests for serial number extraction code """
 
diff --git a/InvenTree/stock/views.py b/InvenTree/stock/views.py
index 29b5c5d6bb..26a957a644 100644
--- a/InvenTree/stock/views.py
+++ b/InvenTree/stock/views.py
@@ -223,6 +223,9 @@ class StockExport(AjaxView):
         stock_items = stock_items.filter(customer=None)
         stock_items = stock_items.filter(belongs_to=None)
 
+        # Pre-fetch related fields to reduce DB queries
+        stock_items = stock_items.prefetch_related('part', 'supplier_part__supplier', 'location', 'purchase_order', 'build')
+
         # Column headers
         headers = [
             _('Stock ID'),