diff --git a/download_from_google_storage.py b/download_from_google_storage.py
index 766a2b855..f98557773 100755
--- a/download_from_google_storage.py
+++ b/download_from_google_storage.py
@@ -32,6 +32,14 @@ class InvalidFileError(IOError):
   pass
 
 
+def GetNormalizedPlatform():
+  """Returns the result of sys.platform accounting for cygwin.
+  Under cygwin, this will always return "win32" like the native Python."""
+  if sys.platform == 'cygwin':
+    return 'win32'
+  return sys.platform
+
+
 # Common utilities
 class Gsutil(object):
   """Call gsutil with some predefined settings.  This is a convenience object,
@@ -197,7 +205,7 @@ def _downloader_worker_thread(thread_num, q, force, base_url,
     # TODO(hinoka): It is supposedly faster to use "gsutil stat" but that
     # doesn't appear to be supported by the gsutil currently in our tree. When
     # we update, this code should use that instead of "gsutil ls -L".
-    if not sys.platform.startswith('win'):
+    if sys.platform != 'win32':
       code, out, _ = gsutil.check_call('ls', '-L', file_url)
       if code != 0:
         out_q.put('%d> %s' % (thread_num, err))
diff --git a/gn.py b/gn.py
index c8af3302e..23521e3ab 100644
--- a/gn.py
+++ b/gn.py
@@ -43,7 +43,7 @@ def FindSourceRootOnPath():
 def RunGN(sourceroot):
   # The binaries in platform-specific subdirectories in src/tools/gn/bin.
   gnpath = sourceroot + '/tools/gn/bin/'
-  if sys.platform == 'win32':
+  if sys.platform in ('cygwin', 'win32'):
     gnpath += 'win/gn.exe'
   elif sys.platform.startswith('linux'):
     gnpath += 'linux/gn'