diff --git a/openerp/tools/mail.py b/openerp/tools/mail.py
index ab376411d65..85dcfd368fe 100644
--- a/openerp/tools/mail.py
+++ b/openerp/tools/mail.py
@@ -100,6 +100,8 @@ def html_sanitize(src, silent=True, strict=False):
         cleaned = cleaned.replace('%7B', '{')
         cleaned = cleaned.replace('%7D', '}')
         cleaned = cleaned.replace('%20', ' ')
+        cleaned = cleaned.replace('%5B', '[')
+        cleaned = cleaned.replace('%5D', ']')
     except etree.ParserError, e:
         if 'empty' in str(e):
             return ""