diff --git a/django/db/models/sql/subqueries.py b/django/db/models/sql/subqueries.py
index 6b52729f68..a066dfeca8 100644
--- a/django/db/models/sql/subqueries.py
+++ b/django/db/models/sql/subqueries.py
@@ -131,7 +131,7 @@ class UpdateQuery(Query):
         for model, values in self.related_updates.iteritems():
             query = UpdateQuery(model)
             query.values = values
-            if self.related_ids:
+            if self.related_ids is not None:
                 query.add_filter(('pk__in', self.related_ids))
             result.append(query)
         return result
diff --git a/tests/modeltests/update/models.py b/tests/modeltests/update/models.py
index 0ffd029437..9ce672f2b3 100644
--- a/tests/modeltests/update/models.py
+++ b/tests/modeltests/update/models.py
@@ -21,6 +21,19 @@ class RelatedPoint(models.Model):
         return unicode(self.name)
 
 
+class A(models.Model):
+    x = models.IntegerField(default=10)
+
+class B(models.Model):
+    a = models.ForeignKey(A)
+    y = models.IntegerField(default=10)
+
+class C(models.Model):
+    y = models.IntegerField(default=10)
+
+class D(C):
+    a = models.ForeignKey(A)
+
 __test__ = {'API_TESTS': """
 >>> DataPoint(name="d0", value="apple").save()
 >>> DataPoint(name="d2", value="banana").save()
diff --git a/tests/modeltests/update/tests.py b/tests/modeltests/update/tests.py
new file mode 100644
index 0000000000..05397f8306
--- /dev/null
+++ b/tests/modeltests/update/tests.py
@@ -0,0 +1,49 @@
+from django.test import TestCase
+
+from models import A, B, D
+
+class SimpleTest(TestCase):
+    def setUp(self):
+        self.a1 = A.objects.create()
+        self.a2 = A.objects.create()
+        for x in range(20):
+            B.objects.create(a=self.a1)
+            D.objects.create(a=self.a1)
+
+    def test_nonempty_update(self):
+        """
+        Test that update changes the right number of rows for a nonempty queryset
+        """
+        num_updated = self.a1.b_set.update(y=100)
+        self.failUnlessEqual(num_updated, 20)
+        cnt = B.objects.filter(y=100).count()
+        self.failUnlessEqual(cnt, 20)
+
+    def test_empty_update(self):
+        """
+        Test that update changes the right number of rows for an empty queryset
+        """
+        num_updated = self.a2.b_set.update(y=100)
+        self.failUnlessEqual(num_updated, 0)
+        cnt = B.objects.filter(y=100).count()
+        self.failUnlessEqual(cnt, 0)
+
+    def test_nonempty_update_with_inheritance(self):
+        """
+        Test that update changes the right number of rows for an empty queryset
+        when the update affects only a base table
+        """
+        num_updated = self.a1.d_set.update(y=100)
+        self.failUnlessEqual(num_updated, 20)
+        cnt = D.objects.filter(y=100).count()
+        self.failUnlessEqual(cnt, 20)
+
+    def test_empty_update_with_inheritance(self):
+        """
+        Test that update changes the right number of rows for an empty queryset
+        when the update affects only a base table
+        """
+        num_updated = self.a2.d_set.update(y=100)
+        self.failUnlessEqual(num_updated, 0)
+        cnt = D.objects.filter(y=100).count()
+        self.failUnlessEqual(cnt, 0)