diff --git a/openslides/projector/projector.py b/openslides/projector/projector.py
index 885c4291d..6e3129f4b 100644
--- a/openslides/projector/projector.py
+++ b/openslides/projector/projector.py
@@ -49,6 +49,8 @@ class SlideMixin(object):
         """
         Return True, if the the slide is the active slide.
         """
+        if self.id is None:
+            return False
         from openslides.projector.api import get_active_slide
         return get_active_slide(only_sid=True) == self.sid
 
diff --git a/tests/agenda/__init__.py b/tests/agenda/__init__.py
new file mode 100644
index 000000000..e69de29bb
diff --git a/tests/agenda/models.py b/tests/agenda/models.py
new file mode 100644
index 000000000..f61694356
--- /dev/null
+++ b/tests/agenda/models.py
@@ -0,0 +1,18 @@
+from django.db import models
+
+from openslides.projector.projector import SlideMixin
+from openslides.projector.api import register_slidemodel
+
+
+class ReleatedItem(SlideMixin, models.Model):
+    prefix = 'releateditem'
+
+    name = models.CharField(max_length='255')
+
+    def get_agenda_title(self):
+        return self.name
+
+    def get_agenda_title_supplement(self):
+        return 'test item'
+
+register_slidemodel(ReleatedItem)
diff --git a/tests/test_agenda.py b/tests/agenda/tests.py
similarity index 92%
rename from tests/test_agenda.py
rename to tests/agenda/tests.py
index 14fcf78e2..05c582f66 100644
--- a/tests/test_agenda.py
+++ b/tests/agenda/tests.py
@@ -19,6 +19,8 @@ from openslides.participant.models import User
 from openslides.agenda.models import Item
 from openslides.agenda.slides import agenda_show
 
+from .models import ReleatedItem
+
 
 class ItemTest(TestCase):
     def setUp(self):
@@ -26,6 +28,8 @@ class ItemTest(TestCase):
         self.item2 = Item.objects.create(title='item2')
         self.item3 = Item.objects.create(title='item1A', parent=self.item1)
         self.item4 = Item.objects.create(title='item1Aa', parent=self.item3)
+        self.releated = ReleatedItem.objects.create(name='foo')
+        self.item5 = Item.objects.create(title='item5', related_sid=self.releated.sid)
 
     def testClosed(self):
         self.assertFalse(self.item1.closed)
@@ -47,11 +51,6 @@ class ItemTest(TestCase):
         self.assertTrue(self.item3 in self.item1.get_children())
         self.assertFalse(self.item4 in self.item1.get_children())
 
-        l = Item.objects.all()
-        self.assertEqual(
-            str(l),
-            "[<Item: item1>, <Item: item1A>, <Item: item1Aa>, <Item: item2>]")
-
     def testForms(self):
         for item in Item.objects.all():
             initial = item.weight_form.initial
@@ -89,6 +88,13 @@ class ItemTest(TestCase):
         self.assertEqual(data['template'], 'projector/AgendaSummary.html')
         self.assertEqual(data['title'], 'Agenda')
 
+    def test_releated_item(self):
+        self.assertEqual(self.item5.get_title(), self.releated.name)
+        self.assertEqual(self.item5.get_title_supplement(), 'test item')
+        self.assertEqual(self.item5.get_related_type(), 'releateditem')
+        self.assertEqual(self.item5.print_related_type(), 'Releateditem')
+
+
 
 class ViewTest(TestCase):
     def setUp(self):