diff --git a/kallithea/lib/vcs/backends/git/repository.py b/kallithea/lib/vcs/backends/git/repository.py
--- a/kallithea/lib/vcs/backends/git/repository.py
+++ b/kallithea/lib/vcs/backends/git/repository.py
@@ -634,8 +634,7 @@ class GitRepository(BaseRepository):
         if path:
             cmd += ['--', path]
 
-        stdout, stderr = self.run_git_command(cmd)
-        # TODO: don't ignore stderr
+        stdout, stderr = self._run_git_command(cmd, cwd=self.path)
         # If we used 'show' command, strip first few lines (until actual diff
         # starts)
         if rev1 == self.EMPTY_CHANGESET:
diff --git a/kallithea/tests/vcs/test_git.py b/kallithea/tests/vcs/test_git.py
--- a/kallithea/tests/vcs/test_git.py
+++ b/kallithea/tests/vcs/test_git.py
@@ -665,65 +665,65 @@ class TestGitSpecificWithRepo(_BackendTe
         assert self.repo.workdir.get_branch() == 'master'
 
     def test_get_diff_runs_git_command_with_hashes(self):
-        self.repo.run_git_command = mock.Mock(return_value=['', ''])
+        self.repo._run_git_command = mock.Mock(return_value=(b'', b''))
         self.repo.get_diff(0, 1)
-        self.repo.run_git_command.assert_called_once_with(
+        self.repo._run_git_command.assert_called_once_with(
             ['diff', '-U3', '--full-index', '--binary', '-p', '-M', '--abbrev=40',
-             self.repo._get_revision(0), self.repo._get_revision(1)])
+             self.repo._get_revision(0), self.repo._get_revision(1)], cwd=self.repo.path)
 
     def test_get_diff_runs_git_command_with_str_hashes(self):
-        self.repo.run_git_command = mock.Mock(return_value=['', ''])
+        self.repo._run_git_command = mock.Mock(return_value=(b'', b''))
         self.repo.get_diff(self.repo.EMPTY_CHANGESET, 1)
-        self.repo.run_git_command.assert_called_once_with(
+        self.repo._run_git_command.assert_called_once_with(
             ['show', '-U3', '--full-index', '--binary', '-p', '-M', '--abbrev=40',
-             self.repo._get_revision(1)])
+             self.repo._get_revision(1)], cwd=self.repo.path)
 
     def test_get_diff_runs_git_command_with_path_if_its_given(self):
-        self.repo.run_git_command = mock.Mock(return_value=['', ''])
+        self.repo._run_git_command = mock.Mock(return_value=(b'', b''))
         self.repo.get_diff(0, 1, 'foo')
-        self.repo.run_git_command.assert_called_once_with(
+        self.repo._run_git_command.assert_called_once_with(
             ['diff', '-U3', '--full-index', '--binary', '-p', '-M', '--abbrev=40',
-             self.repo._get_revision(0), self.repo._get_revision(1), '--', 'foo'])
+             self.repo._get_revision(0), self.repo._get_revision(1), '--', 'foo'], cwd=self.repo.path)
 
     def test_get_diff_does_not_sanitize_valid_context(self):
         almost_overflowed_long_int = 2**31-1
 
-        self.repo.run_git_command = mock.Mock(return_value=['', ''])
+        self.repo._run_git_command = mock.Mock(return_value=(b'', b''))
         self.repo.get_diff(0, 1, 'foo', context=almost_overflowed_long_int)
-        self.repo.run_git_command.assert_called_once_with(
+        self.repo._run_git_command.assert_called_once_with(
             ['diff', '-U' + str(almost_overflowed_long_int), '--full-index', '--binary', '-p', '-M', '--abbrev=40',
-             self.repo._get_revision(0), self.repo._get_revision(1), '--', 'foo'])
+             self.repo._get_revision(0), self.repo._get_revision(1), '--', 'foo'], cwd=self.repo.path)
 
     def test_get_diff_sanitizes_overflowing_context(self):
         overflowed_long_int = 2**31
         sanitized_overflowed_long_int = overflowed_long_int-1
 
-        self.repo.run_git_command = mock.Mock(return_value=['', ''])
+        self.repo._run_git_command = mock.Mock(return_value=(b'', b''))
         self.repo.get_diff(0, 1, 'foo', context=overflowed_long_int)
 
-        self.repo.run_git_command.assert_called_once_with(
+        self.repo._run_git_command.assert_called_once_with(
             ['diff', '-U' + str(sanitized_overflowed_long_int), '--full-index', '--binary', '-p', '-M', '--abbrev=40',
-             self.repo._get_revision(0), self.repo._get_revision(1), '--', 'foo'])
+             self.repo._get_revision(0), self.repo._get_revision(1), '--', 'foo'], cwd=self.repo.path)
 
     def test_get_diff_does_not_sanitize_zero_context(self):
         zero_context = 0
 
-        self.repo.run_git_command = mock.Mock(return_value=['', ''])
+        self.repo._run_git_command = mock.Mock(return_value=(b'', b''))
         self.repo.get_diff(0, 1, 'foo', context=zero_context)
 
-        self.repo.run_git_command.assert_called_once_with(
+        self.repo._run_git_command.assert_called_once_with(
             ['diff', '-U' + str(zero_context), '--full-index', '--binary', '-p', '-M', '--abbrev=40',
-             self.repo._get_revision(0), self.repo._get_revision(1), '--', 'foo'])
+             self.repo._get_revision(0), self.repo._get_revision(1), '--', 'foo'], cwd=self.repo.path)
 
     def test_get_diff_sanitizes_negative_context(self):
         negative_context = -10
 
-        self.repo.run_git_command = mock.Mock(return_value=['', ''])
+        self.repo._run_git_command = mock.Mock(return_value=(b'', b''))
         self.repo.get_diff(0, 1, 'foo', context=negative_context)
 
-        self.repo.run_git_command.assert_called_once_with(
+        self.repo._run_git_command.assert_called_once_with(
             ['diff', '-U0', '--full-index', '--binary', '-p', '-M', '--abbrev=40',
-             self.repo._get_revision(0), self.repo._get_revision(1), '--', 'foo'])
+             self.repo._get_revision(0), self.repo._get_revision(1), '--', 'foo'], cwd=self.repo.path)
 
 
 class TestGitRegression(_BackendTestMixin):