diff -Naur Python-3.4.3.orig/Lib/distutils/tests/test_util.py Python-3.4.3/Lib/distutils/tests/test_util.py
--- Python-3.4.3.orig/Lib/distutils/tests/test_util.py	2015-02-25 11:27:44.000000000 +0000
+++ Python-3.4.3/Lib/distutils/tests/test_util.py	2015-05-29 10:29:16.152123848 +0000
@@ -208,6 +208,8 @@
             return '/'.join(path)
         os.path.join = _join
 
+        self.assertEqual(change_root('/root', '//old/its/here'),
+                         '/root/old/its/here')
         self.assertEqual(change_root('/root', '/old/its/here'),
                          '/root/old/its/here')
         self.assertEqual(change_root('/root', 'its/here'),
diff -Naur Python-3.4.3.orig/Lib/distutils/util.py Python-3.4.3/Lib/distutils/util.py
--- Python-3.4.3.orig/Lib/distutils/util.py	2015-02-25 11:27:44.000000000 +0000
+++ Python-3.4.3/Lib/distutils/util.py	2015-05-29 10:31:44.199114154 +0000
@@ -140,20 +140,11 @@
     """Return 'pathname' with 'new_root' prepended.  If 'pathname' is
     relative, this is equivalent to "os.path.join(new_root,pathname)".
     Otherwise, it requires making 'pathname' relative and then joining the
-    two, which is tricky on DOS/Windows and Mac OS.
+    two.
     """
-    if os.name == 'posix':
-        if not os.path.isabs(pathname):
-            return os.path.join(new_root, pathname)
-        else:
-            return os.path.join(new_root, pathname[1:])
-
-    elif os.name == 'nt':
+    if os.name in ['posix', 'nt', 'os2']:
         (drive, path) = os.path.splitdrive(pathname)
-        if path[0] == '\\':
-            path = path[1:]
-        return os.path.join(new_root, path)
-
+        return os.path.join(new_root, path.lstrip(os.sep))
     else:
         raise DistutilsPlatformError("nothing known about platform '%s'" % os.name)