diff --git a/addons/email_template/email_template.py b/addons/email_template/email_template.py
index acd1aed24de..86f136ca5b9 100644
--- a/addons/email_template/email_template.py
+++ b/addons/email_template/email_template.py
@@ -57,6 +57,8 @@ class email_template(osv.osv):
            :param int res_id: id of the document record this mail is related to.
         """
         if not template: return u""
+        if context is None:
+            context = {}
         try:
             template = tools.ustr(template)
             record = None