diff --git a/ceilometer/compute/libvirt.py b/ceilometer/compute/libvirt.py
index c6c0d8020..c389c994e 100644
--- a/ceilometer/compute/libvirt.py
+++ b/ceilometer/compute/libvirt.py
@@ -18,7 +18,6 @@
 
 import copy
 import datetime
-import multiprocessing
 
 from lxml import etree
 
@@ -167,8 +166,7 @@ class CPUPollster(LibVirtPollster):
             prev_timestamp = prev_times[1]
             delta = self.utilization_map[instance.id][1] - prev_timestamp
             elapsed = (delta.seconds * (10 ** 6) + delta.microseconds) * 1000
-            cores_fraction = (instance.flavor['vcpus'] * 1.0 /
-                              multiprocessing.cpu_count())
+            cores_fraction = 1.0 / cpu_info['num_cpu']
             # account for cpu_time being reset when the instance is restarted
             time_used = (cpu_info['cpu_time'] - prev_cpu
                          if prev_cpu <= cpu_info['cpu_time'] else
diff --git a/ceilometer/nova_client.py b/ceilometer/nova_client.py
index 470182caa..77359db5e 100644
--- a/ceilometer/nova_client.py
+++ b/ceilometer/nova_client.py
@@ -54,7 +54,6 @@ class Client(object):
         for instance in instances:
             fid = instance.flavor['id']
             instance.flavor['name'] = flavors[fid].name
-            instance.flavor['vcpus'] = flavors[fid].vcpus
         return instances
 
     @logged
diff --git a/tests/compute/test_libvirt.py b/tests/compute/test_libvirt.py
index b306addbf..5983550ef 100644
--- a/tests/compute/test_libvirt.py
+++ b/tests/compute/test_libvirt.py
@@ -59,7 +59,7 @@ class TestLibvirtBase(test_base.TestCase):
         setattr(self.instance, 'OS-EXT-SRV-ATTR:instance_name',
                 self.instance.name)
         self.instance.id = 1
-        self.instance.flavor = {'name': 'm1.small', 'id': 2, 'vcpus': 1}
+        self.instance.flavor = {'name': 'm1.small', 'id': 2}
         flags.FLAGS.compute_driver = 'libvirt.LibvirtDriver'
         flags.FLAGS.connection_type = 'libvirt'
 
@@ -215,16 +215,15 @@ class TestCPUPollster(TestLibvirtBase):
         self.pollster = libvirt.CPUPollster()
 
     def test_get_counter(self):
-        self.instance.vcpus = 1
         conn = fake_libvirt_conn(self.mox, 3)
         self.mox.StubOutWithMock(conn, 'get_info')
         conn.get_info({'name': self.instance.name}).AndReturn(
-            {'cpu_time': 1 * (10 ** 6)})
+            {'cpu_time': 1 * (10 ** 6), 'num_cpu': 2})
         conn.get_info({'name': self.instance.name}).AndReturn(
-            {'cpu_time': 3 * (10 ** 6)})
+            {'cpu_time': 3 * (10 ** 6), 'num_cpu': 2})
         # cpu_time resets on instance restart
         conn.get_info({'name': self.instance.name}).AndReturn(
-            {'cpu_time': 2 * (10 ** 6)})
+            {'cpu_time': 2 * (10 ** 6), 'num_cpu': 2})
         self.mox.ReplayAll()
 
         def _verify_cpu_metering(zero, expected_time):