diff --git a/kallithea/lib/vcs/backends/hg/changeset.py b/kallithea/lib/vcs/backends/hg/changeset.py
--- a/kallithea/lib/vcs/backends/hg/changeset.py
+++ b/kallithea/lib/vcs/backends/hg/changeset.py
@@ -246,9 +246,9 @@ class MercurialChangeset(BaseChangeset):
         """
         fctx = self._get_filectx(path)
         if 'x' in fctx.flags():
-            return 0100755
+            return 0o100755
         else:
-            return 0100644
+            return 0o100644
 
     def get_file_content(self, path):
         """
diff --git a/kallithea/lib/vcs/nodes.py b/kallithea/lib/vcs/nodes.py
--- a/kallithea/lib/vcs/nodes.py
+++ b/kallithea/lib/vcs/nodes.py
@@ -255,7 +255,7 @@ class FileNode(Node):
         super(FileNode, self).__init__(path, kind=NodeKind.FILE)
         self.changeset = changeset
         self._content = content
-        self._mode = mode or 0100644
+        self._mode = mode or 0o100644
 
     @LazyProperty
     def mode(self):
diff --git a/kallithea/model/scm.py b/kallithea/model/scm.py
--- a/kallithea/model/scm.py
+++ b/kallithea/model/scm.py
@@ -750,7 +750,7 @@ class ScmModel(object):
                     with open(_hook_file, 'wb') as f:
                         tmpl = tmpl.replace('_TMPL_', kallithea.__version__)
                         f.write(tmpl)
-                    os.chmod(_hook_file, 0755)
+                    os.chmod(_hook_file, 0o755)
                 except IOError as e:
                     log.error('error writing %s: %s', _hook_file, e)
             else:
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
@@ -657,7 +657,7 @@ class TestGitSpecificWithRepo(_BackendTe
                 'added': [
                     FileNode('foobar/static/js/admin/base.js', content='base'),
                     FileNode('foobar/static/admin', content='admin',
-                        mode=0120000), # this is a link
+                        mode=0o120000), # this is a link
                     FileNode('foo', content='foo'),
                 ],
             },
diff --git a/kallithea/tests/vcs/test_nodes.py b/kallithea/tests/vcs/test_nodes.py
--- a/kallithea/tests/vcs/test_nodes.py
+++ b/kallithea/tests/vcs/test_nodes.py
@@ -144,13 +144,13 @@ class TestNodeBasic(object):
         assert not mode & stat.S_IXOTH
 
     def test_file_node_is_executable(self):
-        node = FileNode('foobar', 'empty... almost', mode=0100755)
+        node = FileNode('foobar', 'empty... almost', mode=0o100755)
         assert node.is_executable
 
-        node = FileNode('foobar', 'empty... almost', mode=0100500)
+        node = FileNode('foobar', 'empty... almost', mode=0o100500)
         assert node.is_executable
 
-        node = FileNode('foobar', 'empty... almost', mode=0100644)
+        node = FileNode('foobar', 'empty... almost', mode=0o100644)
         assert not node.is_executable
 
     def test_mimetype(self):