--- a/pylib/mozreview/mozreview/bugzilla/client.py
+++ b/pylib/mozreview/mozreview/bugzilla/client.py
@@ -177,17 +177,19 @@ class Bugzilla(object):
         reviewers = reviewers.copy()
         params = self._auth_params({})
         flags = []
         rb_attachment = None
         attachments = self.get_rb_attachments(bug_id)
 
         # Find the associated attachment, then go through the review flags.
         for a in attachments:
-            if a['data'] != url:
+
+            # Make sure we check for old-style URLs as well.
+            if not self._rb_attach_url_matches(a['data'], url):
                 continue
 
             rb_attachment = a
 
             for f in a.get('flags', []):
                 if f['name'] not in ['review', 'feedback']:
                     # We only care about review and feedback flags.
                     continue
@@ -265,20 +267,25 @@ class Bugzilla(object):
             'include_fields': ['id', 'data', 'content_type', 'is_obsolete',
                                'flags']
         })
 
         return [a for a
                 in self.proxy.Bug.attachments(params)['bugs'][str(bug_id)]
                 if a['content_type'] == 'text/x-review-board-request']
 
+    def _rb_attach_url_matches(self, attach_url, rb_url):
+        # Make sure we check for old-style URLs as well.
+        return (attach_url == rb_url or
+                '%sdiff/#index_header' % attach_url == rb_url)
+
     def _get_review_request_attachment(self, bug_id, rb_url):
         """Obtain a Bugzilla attachment for a review request."""
         for a in self.get_rb_attachments(bug_id):
-            if a.get('data') == rb_url:
+            if self._rb_attach_url_matches(a.get('data'), rb_url):
                 return a
 
         return None
 
     @xmlrpc_to_bugzilla_errors
     def r_plus_attachment(self, bug_id, reviewer, rb_url, comment=None):
         """Set a review flag to "+".
 
@@ -371,17 +378,18 @@ class Bugzilla(object):
         want to leave any lingering references in Bugzilla.
         """
         params = self._auth_params({
             'ids': [],
             'is_obsolete': True,
         })
 
         for a in self.get_rb_attachments(bug_id):
-            if a.get('data') == rb_url and not a.get('is_obsolete'):
+            if (self._rb_attach_url_matches(a.get('data'), rb_url) and
+                not a.get('is_obsolete')):
                 params['ids'].append(a['id'])
 
         if params['ids']:
             self.proxy.Bug.update_attachment(params)
 
     @xmlrpc_to_bugzilla_errors
     def valid_api_key(self, username, api_key):
         try: