diff --git a/rhodecode/controllers/compare.py b/rhodecode/controllers/compare.py
--- a/rhodecode/controllers/compare.py
+++ b/rhodecode/controllers/compare.py
@@ -161,7 +161,10 @@ class CompareController(BaseRepoControll
 
         diff_limit = self.cut_off_limit if not c.fulldiff else None
 
-        _diff = diffs.differ(org_repo, org_ref, other_repo, other_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)
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)
diff --git a/rhodecode/lib/diffs.py b/rhodecode/lib/diffs.py
--- a/rhodecode/lib/diffs.py
+++ b/rhodecode/lib/diffs.py
@@ -682,36 +682,3 @@ class DiffProcessor(object):
         Returns tuple of added, and removed lines for this instance
         """
         return self.adds, self.removes
-
-
-def differ(org_repo, org_ref, other_repo, other_ref,
-           context=3, ignore_whitespace=False):
-    """
-    General differ between branches, bookmarks, revisions of two remote or
-    local but related repositories
-
-    :param org_repo:
-    :param org_ref:
-    :param other_repo:
-    :type other_repo:
-    :type other_ref:
-    """
-
-    org_repo_scm = org_repo.scm_instance
-    other_repo_scm = other_repo.scm_instance
-
-    org_repo = org_repo_scm._repo
-    other_repo = other_repo_scm._repo
-
-    org_ref = safe_str(org_ref[1])
-    other_ref = safe_str(other_ref[1])
-
-    if org_repo_scm == other_repo_scm:
-        log.debug('running diff between %s@%s and %s@%s'
-                  % (org_repo.path, org_ref,
-                     other_repo.path, other_ref))
-        _diff = org_repo_scm.get_diff(rev1=org_ref, rev2=other_ref,
-            ignore_whitespace=ignore_whitespace, context=context)
-        return _diff
-
-    return '' # FIXME: when is it ever relevant to return nothing?