diff --git a/django/db/models/base.py b/django/db/models/base.py
--- a/django/db/models/base.py
+++ b/django/db/models/base.py
@@ -526,9 +526,10 @@
                     # It does already exist, so do an UPDATE.
                     if force_update or non_pks:
                         values = [(f, None, (raw and getattr(self, f.attname) or f.pre_save(self, False))) for f in non_pks]
-                        rows = manager.using(using).filter(pk=pk_val)._update(values)
-                        if force_update and not rows:
-                            raise DatabaseError("Forced update did not affect any rows.")
+                        if values:
+                            rows = manager.using(using).filter(pk=pk_val)._update(values)
+                            if force_update and not rows:
+                                raise DatabaseError("Forced update did not affect any rows.")
                 else:
                     record_exists = False
             if not pk_set or not record_exists:
diff --git a/tests/modeltests/force_insert_update/models.py b/tests/modeltests/force_insert_update/models.py
--- a/tests/modeltests/force_insert_update/models.py
+++ b/tests/modeltests/force_insert_update/models.py
@@ -8,6 +8,20 @@
     name = models.CharField(max_length = 10)
     value = models.IntegerField()
 
+
+class InheritedCounter(Counter):
+    tag = models.CharField(max_length=10)
+
+
+class ProxyCounter(Counter):
+    class Meta:
+        proxy = True
+
+
+class SubCounter(Counter):
+    pass
+
+
 class WithCustomPK(models.Model):
     name = models.IntegerField(primary_key=True)
     value = models.IntegerField()
diff --git a/tests/modeltests/force_insert_update/tests.py b/tests/modeltests/force_insert_update/tests.py
--- a/tests/modeltests/force_insert_update/tests.py
+++ b/tests/modeltests/force_insert_update/tests.py
@@ -1,16 +1,18 @@
 from django.db import transaction, IntegrityError, DatabaseError
 from django.test import TestCase
 
-from models import Counter, WithCustomPK
+from models import (Counter, WithCustomPK, InheritedCounter, ProxyCounter,
+        SubCounter)
 
 
 class ForceTests(TestCase):
     def test_force_update(self):
         c = Counter.objects.create(name="one", value=1)
+
         # The normal case
-
         c.value = 2
         c.save()
+
         # Same thing, via an update
         c.value = 3
         c.save(force_update=True)
@@ -36,3 +38,25 @@
         # the data isn't in the database already.
         obj = WithCustomPK(name=1, value=1)
         self.assertRaises(DatabaseError, obj.save, force_update=True)
+
+
+class InheritanceTests(TestCase):
+    def test_force_update_on_inherited_model(self):
+        a = InheritedCounter(name="count", value=1, tag="spam")
+        a.save()
+        a.save(force_update=True)
+
+    def test_force_update_on_proxy_model(self):
+        a = ProxyCounter(name="count", value=1)
+        a.save()
+        a.save(force_update=True)
+
+    def test_force_update_on_inherited_model_without_fields(self):
+        '''
+        Issue 13864: force_update fails on subclassed models, if they don't
+        specify custom fields.
+        '''
+        a = SubCounter(name="count", value=1)
+        a.save()
+        a.value = 2
+        a.save(force_update=True)