diff --git a/tuned/admin/admin.py b/tuned/admin/admin.py
index 3f84413..22ffcde 100644
--- a/tuned/admin/admin.py
+++ b/tuned/admin/admin.py
@@ -73,7 +73,7 @@ class Admin(object):
 			action = getattr(self, "_action_" + action_name)
 		except AttributeError as e:
 			if not self._dbus:
-				self._error(e + ", action '%s' is not implemented" % action_name)
+				self._error(str(e) + ", action '%s' is not implemented" % action_name)
 				return False
 		if self._dbus:
 			try: