diff --git a/contrib/boobank-munin b/contrib/boobank-munin
index 3f07e3a6..f48d5dc9 100755
--- a/contrib/boobank-munin
+++ b/contrib/boobank-munin
@@ -21,6 +21,7 @@
 
 import os
 import sys
+import locale
 import time
 import logging
 from weboob.core import Weboob, CallErrors
@@ -179,7 +180,7 @@ class BoobankMuninPlugin(object):
 
     def print_errors(self, errors):
         for backend, err, backtrace in errors:
-            print >>sys.stderr, '%s(%s): %s' % (type(err).__name__, backend.name, err)
+            print >>sys.stderr, (u'%s(%s): %s' % (type(err).__name__, backend.name, err)).encode(sys.stdout.encoding or locale.getpreferredencoding(), 'replace')
             if isinstance(err, BrowserIncorrectPassword):
                 self.weboob.backends_config.edit_backend(backend.name, backend.NAME, {'_enabled': False})