diff --git a/addons/mail/models/mail_render_mixin.py b/addons/mail/models/mail_render_mixin.py
index fdb6d76de1e..331816941e2 100644
--- a/addons/mail/models/mail_render_mixin.py
+++ b/addons/mail/models/mail_render_mixin.py
@@ -154,9 +154,9 @@ class MailRenderMixin(models.AbstractModel):
             r"""( # Group 1: element up to url in style
                 <[^>]+\bstyle=" # Element with a style attribute
                 [^"]+\burl\( # Style attribute contains "url(" style
-                (?:&\#34;|'|&quot;)?) # url style may start with (escaped) quote: capture it
+                (?:&\#34;|'|&quot;|&\#39;)?) # url style may start with (escaped) quote: capture it
             ( # Group 2: url itself
-                /(?:[^'")]|(?!&\#34;))+ # stop at the first closing quote
+                /(?:[^'")]|(?!&\#34;)|(?!&\#39;))+ # stop at the first closing quote
         )""", re.VERBOSE), _sub_relative2absolute, html)
 
         return wrapper(html)