diff --git a/README.rst b/README.rst
index 50f985b..84ea77e 100644
--- a/README.rst
+++ b/README.rst
@@ -37,7 +37,7 @@ Check OpenBGPD Nagios|Icinga|shinken|etc plugin.
 usage
 -------
 
-This check *runs bgpctl show* and check that all bgp sessions are up.
+This check runs **bgpctl show** and checks that all bgp sessions are up.
 
 
 sample outputs :
@@ -67,7 +67,7 @@ sample outputs :
     ::
       
      $ check_openbgpd
-     CHECKBGPCTL CRITICAL - OTHER-PEER is idle (outside range 0:) | 'PEER-1'=529918;;;0 'OTHER-PEER'=None;;;0
+     CHECKBGPCTL CRITICAL - OTHER-PEER is U (outside range 0:) | 'PEER-1'=529918;;;0 'OTHER-PEER'=U;;;0
     
     
 + Unknown
diff --git a/docs/CHANGES.rst b/docs/CHANGES.rst
index 3b42a49..51aac49 100644
--- a/docs/CHANGES.rst
+++ b/docs/CHANGES.rst
@@ -5,7 +5,7 @@ Changelog
 0.7 (unreleased)
 ----------------
 
-- Nothing changed yet.
+- fix 'idle' breaks performance data rendering https://github.com/jpcw/checkopenbgpd/issues/1
 
 
 0.6 (2015-04-09)
diff --git a/src/checkopenbgpd/checkopenbgpd.py b/src/checkopenbgpd/checkopenbgpd.py
index 2691123..94456bb 100644
--- a/src/checkopenbgpd/checkopenbgpd.py
+++ b/src/checkopenbgpd/checkopenbgpd.py
@@ -69,17 +69,18 @@ def _get_sessions(self):
 
     def check_session(self, session):
         """check session is up, or not in idle list if idle."""
+        result = 'U'
         state = session.State_PrfRcvd
 
         if state.isdigit():
-            return int(state)
+            result = int(state)
 
         if state == 'Idle':
             if self.idle_list is not None:
                 if session.Neighbor in self.idle_list:
-                    return 0
+                    result = 0
 
-            return 'idle'
+        return result
 
     def probe(self):
         """."""
diff --git a/src/checkopenbgpd/tests/test_checkopenbgpd.py b/src/checkopenbgpd/tests/test_checkopenbgpd.py
index 7a5ad4c..ac1e42e 100644
--- a/src/checkopenbgpd/tests/test_checkopenbgpd.py
+++ b/src/checkopenbgpd/tests/test_checkopenbgpd.py
@@ -80,7 +80,7 @@ def test_check_idle_session_not_in_idle_list(self):
             _popen.return_value = output, ''
             sessions = check._get_sessions()
             result = check.check_session(sessions[0])
-            self.assertIsNone(result)
+            self.assertEquals(result, 'U')
 
     def test_check_probe_without_idle_list(self):
         check = checkopenbgpd.CheckBgpCtl(None)
@@ -92,11 +92,11 @@ def test_check_probe_without_idle_list(self):
             probe = check.probe()
             first = next(probe)
             self.assertEqual(type(first), Metric)
-            self.assertIsNone(first.value)
+            self.assertEquals(first.value, 'U')
             second = next(probe)
             self.assertEquals(second.value, 529001)
             third = next(probe)
-            self.assertEquals(third.value, 'idle')
+            self.assertEquals(third.value, 'U')
 
     def test_check_probe_with_idle_list(self):
         check = checkopenbgpd.CheckBgpCtl(['THIRD'])
@@ -108,7 +108,7 @@ def test_check_probe_with_idle_list(self):
             probe = check.probe()
             first = next(probe)
             self.assertEqual(type(first), Metric)
-            self.assertIsNone(first.value)
+            self.assertEquals(first.value, 'U')
             second = next(probe)
             self.assertEquals(second.value, 529001)
             third = next(probe)