diff --git a/contrib/munin/generic/generic-munin b/contrib/munin/generic/generic-munin
index 2d709a95..c8d28df0 100755
--- a/contrib/munin/generic/generic-munin
+++ b/contrib/munin/generic/generic-munin
@@ -24,6 +24,7 @@ import sys
 import locale
 import time
 import logging
+from weboob.capabilities.base import NotAvailable
 from weboob.core import Weboob, CallErrors
 from weboob.tools.browser import BrowserIncorrectPassword
 
@@ -261,7 +262,8 @@ class GenericMuninPlugin(object):
             for backend, result in self.build_do():
                 if self.monitored(result):
                     value = self.get_value(result)
-                    self.write_output('%s.value %f' % (self.result2id(result), value))
+                    if value is not NotAvailable:
+                        self.write_output('%s.value %f' % (self.result2id(result), value))
         except CallErrors, errors:
             self.print_errors(errors)
             self.print_cache(self.name)