diff --git a/addons/email_template/email_template.py b/addons/email_template/email_template.py
index 335b67fcfb1..c5e24b0da5f 100644
--- a/addons/email_template/email_template.py
+++ b/addons/email_template/email_template.py
@@ -319,7 +319,8 @@ class email_template(osv.osv):
                                                  or False
         if template.user_signature:
             signature = self.pool.get('res.users').browse(cr, uid, uid, context).signature
-            values['body_html'] = tools.append_content_to_html(values['body_html'], signature)
+            if signature:
+                values['body_html'] = tools.append_content_to_html(values['body_html'], signature)
 
         if values['body_html']:
             values['body'] = tools.html_sanitize(values['body_html'])