diff --git a/tryton/common/cellrendererdate.py b/tryton/common/cellrendererdate.py
index 92a204fd2f..7dfd500a94 100644
--- a/tryton/common/cellrendererdate.py
+++ b/tryton/common/cellrendererdate.py
@@ -2,6 +2,7 @@
 #this repository contains the full copyright notices and license terms.
 import gtk
 import gobject
+import pango
 from date_widget import mapping, DateEntry, compute_date