diff --git a/tools/android/junction.py b/tools/android/junction.py
index 7dc58b8..97fa8d2 100644
--- a/tools/android/junction.py
+++ b/tools/android/junction.py
@@ -63,7 +63,10 @@
     ...do something else...
   """
 
-  def __init__(self, junction_target, testonly_mkdtemp=None):
+  def __init__(self,
+               junction_target,
+               testonly_mkdtemp=None,
+               testonly_maxpath=None):
     """Initialize this object.
 
     Args:
@@ -72,14 +75,78 @@
       testonly_mkdtemp: function(); for testing only; a custom function that
         returns a temp directory path, you can use it to mock out
         tempfile.mkdtemp
+      testonly_maxpath: int; for testing oly; maximum path length before the
+        path is a "long path" (typically MAX_PATH on Windows)
     """
-    self._target = os.path.normpath(junction_target)
+    self._target = os.path.abspath(junction_target)
     self._junction = None
     self._mkdtemp = testonly_mkdtemp or tempfile.mkdtemp
+    self._max_path = testonly_maxpath or 248
+
+  @staticmethod
+  def _Mklink(name, target):
+    proc = subprocess.Popen(
+        "cmd.exe /C mklink /J \"%s\" \"\\\\?\\%s\"" % (name, target),
+        stdout=subprocess.PIPE,
+        stderr=subprocess.STDOUT)
+    exitcode = proc.wait()
+    if exitcode != 0:
+      stdout = proc.communicate()[0]
+      raise JunctionCreationError(name, target, stdout)
+
+  @staticmethod
+  def _TryMkdir(path):
+    try:
+      os.mkdir(path)
+    except OSError as e:
+      # Another process may have already created this directory.
+      if not os.path.isdir(path):
+        raise IOError("Could not create directory at '%s': %s" % (path, str(e)))
+
+  @staticmethod
+  def _MakeLinks(target, mkdtemp, max_path):
+    """Creates a temp directory and a junction in it, pointing to `target`.
+
+    Creates all parent directories of `target` if they don't exist.
+
+    Args:
+      target: string; path to the directory that is the junction's target
+      mkdtemp: function():string; creates a temp directory and returns its
+        absolute path
+      max_path: int; maximum path length before the path is a "long path"
+        (typically MAX_PATH on Windows)
+    Returns:
+      The full path to the junction.
+    Raises:
+      JunctionCreationError: if `mklink` fails to create a junction
+    """
+    segments = []
+    dirpath = target
+    while not os.path.isdir(dirpath):
+      dirpath, child = os.path.split(dirpath)
+      if child:
+        segments.append(child)
+    tmp = mkdtemp()
+    juncpath = os.path.join(tmp, "j")
+    for child in reversed(segments):
+      childpath = os.path.join(dirpath, child)
+      if len(childpath) >= max_path:
+        try:
+          TempJunction._Mklink(juncpath, dirpath)
+          TempJunction._TryMkdir(os.path.join(juncpath, child))
+        finally:
+          os.rmdir(juncpath)
+      else:
+        TempJunction._TryMkdir(childpath)
+      dirpath = childpath
+    TempJunction._Mklink(juncpath, target)
+    return juncpath
 
   def __enter__(self):
     """Creates a temp directory and a junction in it, pointing to self._target.
 
+    Creates all parent directories of self._target if they don't exist.
+
     This method is automatically called upon entering a `with` statement's body.
 
     Returns:
@@ -87,18 +154,9 @@
     Raises:
       JunctionCreationError: if `mklink` fails to create a junction
     """
-    result = os.path.normpath(os.path.join(self._mkdtemp(), "j"))
-    proc = subprocess.Popen(
-        "cmd.exe /C mklink /J \"%s\" \"\\\\?\\%s\"" %
-        (result, os.path.normpath(self._target)),
-        stdout=subprocess.PIPE,
-        stderr=subprocess.STDOUT)
-    exitcode = proc.wait()
-    if exitcode != 0:
-      stdout = proc.communicate()[0]
-      raise JunctionCreationError(result, self._target, stdout)
-    self._junction = result
-    return result
+    self._junction = TempJunction._MakeLinks(self._target, self._mkdtemp,
+                                             self._max_path)
+    return self._junction
 
   def __exit__(self, unused_type, unused_value, unused_traceback):
     """Deletes the junction and its parent directory.