diff --git a/cabot/cabotapp/models.py b/cabot/cabotapp/models.py
index 19927f6..203253f 100644
--- a/cabot/cabotapp/models.py
+++ b/cabot/cabotapp/models.py
@@ -257,7 +257,7 @@ class Instance(CheckGroupMixin):
         new_instance = self
         new_instance.pk = None
         new_instance.id = None
-        new_instance.name = "Copy of %s" % self.name
+        new_instance.name = u"Copy of %s" % self.name
 
         new_instance.save()
 
@@ -493,10 +493,8 @@ class StatusCheck(PolymorphicModel):
         new_check.id = None
         new_check.last_run = None
         new_check.save()
-        if inst_set:
-            new_check.instance_set.add(*inst_set)
-        if serv_set:
-            new_check.service_set.add(*serv_set)
+        for linked in list(inst_set) + list(serv_set):
+            linked.status_checks.add(new_check)
         return new_check.pk
 
     def update_related_services(self):
diff --git a/cabot/cabotapp/tests/tests_basic.py b/cabot/cabotapp/tests/tests_basic.py
index 785062e..f40bf14 100644
--- a/cabot/cabotapp/tests/tests_basic.py
+++ b/cabot/cabotapp/tests/tests_basic.py
@@ -275,11 +275,19 @@ class TestInstances(LocalTestCase):
             name='Hello',
             address='192.168.0.1',
         )
+        pingcheck = ICMPStatusCheck.objects.create(
+            name='Hello check',
+        )
+        self.instance.status_checks.add(pingcheck)
         self.instance.duplicate()
         instances = Instance.objects.all()
         self.assertEqual(len(instances), 2)
         new = instances.filter(name__icontains='Copy of')[0]
         self.assertEqual(new.name, 'Copy of Hello')
+        old = instances.exclude(name__icontains='Copy of')[0]
+        self.assertEqual(len(new.status_checks.all()), 1)
+        self.assertEqual(len(old.status_checks.all()), 1)
+        self.assertNotEqual(new.status_checks.all()[0], old.status_checks.all()[0])
 
 
 class TestWebInterface(LocalTestCase):
@@ -358,3 +366,4 @@ class TestWebInterface(LocalTestCase):
         check = checks[0]
         self.assertEqual(len(check.problems), 1)
         self.assertEqual(check.success_rate, 50)
+