diff --git a/rhodecode/controllers/pullrequests.py b/rhodecode/controllers/pullrequests.py
--- a/rhodecode/controllers/pullrequests.py
+++ b/rhodecode/controllers/pullrequests.py
@@ -42,6 +42,7 @@ from rhodecode.lib.helpers import Page
 from rhodecode.lib import helpers as h
 from rhodecode.lib import diffs
 from rhodecode.lib.utils import action_logger, jsonify
+from rhodecode.lib.vcs.utils import safe_str
 from rhodecode.lib.vcs.exceptions import EmptyRepositoryError
 from rhodecode.lib.vcs.backends.base import EmptyChangeset
 from rhodecode.lib.diffs import LimitedDiffContainer
@@ -328,7 +329,10 @@ class PullrequestsController(BaseRepoCon
         diff_limit = self.cut_off_limit if not fulldiff else None
 
         #we swap org/other ref since we run a simple diff on one repo
-        _diff = diffs.differ(org_repo, other_ref, other_repo, org_ref)
+        log.debug('running diff between %s@%s and %s@%s'
+                  % (org_repo.scm_instance.path, org_ref,
+                     other_repo.scm_instance.path, other_ref))
+        _diff = org_repo.scm_instance.get_diff(rev1=safe_str(org_ref[1]), rev2=safe_str(other_ref[1]))
 
         diff_processor = diffs.DiffProcessor(_diff or '', format='gitdiff',
                                              diff_limit=diff_limit)