diff --git a/nova/tests/unit/virt/libvirt/test_driver.py b/nova/tests/unit/virt/libvirt/test_driver.py
index 6d8c0cd89356..3e9b3cd622e8 100644
--- a/nova/tests/unit/virt/libvirt/test_driver.py
+++ b/nova/tests/unit/virt/libvirt/test_driver.py
@@ -3914,14 +3914,6 @@ class LibvirtConnTestCase(test.NoDBTestCase):
 
             self._test_get_guest_config_sysinfo_serial(theuuid)
 
-    def test_get_guest_config_sysinfo_serial_invalid(self):
-        self.flags(sysinfo_serial="invalid", group="libvirt")
-
-        self.assertRaises(exception.NovaException,
-                          libvirt_driver.LibvirtDriver,
-                          fake.FakeVirtAPI(),
-                          True)
-
     def _create_fake_service_compute(self):
         service_info = {
             'id': 1729,
diff --git a/nova/virt/libvirt/driver.py b/nova/virt/libvirt/driver.py
index dba409a0a750..4a72e9282e2a 100644
--- a/nova/virt/libvirt/driver.py
+++ b/nova/virt/libvirt/driver.py
@@ -495,13 +495,6 @@ class LibvirtDriver(driver.ComputeDriver):
 
         self._sysinfo_serial_func = sysinfo_serial_funcs.get(
             CONF.libvirt.sysinfo_serial)
-        if not self._sysinfo_serial_func:
-            raise exception.NovaException(
-                _("Unexpected sysinfo_serial setting '%(actual)s'. "
-                  "Permitted values are %(expect)s'") %
-                  {'actual': CONF.libvirt.sysinfo_serial,
-                   'expect': ', '.join("'%s'" % k for k in
-                                       sysinfo_serial_funcs.keys())})
 
         self.job_tracker = instancejobtracker.InstanceJobTracker()
         self._remotefs = remotefs.RemoteFilesystem()