diff --git a/tornado/process.py b/tornado/process.py
index f580e192..daa9677b 100644
--- a/tornado/process.py
+++ b/tornado/process.py
@@ -50,7 +50,14 @@ except NameError:
 
 
 # Re-export this exception for convenience.
-CalledProcessError = subprocess.CalledProcessError
+try:
+    CalledProcessError = subprocess.CalledProcessError
+except AttributeError:
+    # The subprocess module exists in Google App Engine, but is empty.
+    # This module isn't very useful in that case, but it should
+    # at least be importable.
+    if 'APPENGINE_RUNTIME' not in os.environ:
+        raise
 
 
 def cpu_count():
diff --git a/tornado/test/locale_test.py b/tornado/test/locale_test.py
index 44726644..e2578386 100644
--- a/tornado/test/locale_test.py
+++ b/tornado/test/locale_test.py
@@ -7,7 +7,7 @@ import tempfile
 
 import tornado.locale
 from tornado.escape import utf8, to_unicode
-from tornado.test.util import unittest
+from tornado.test.util import unittest, skipOnAppEngine
 from tornado.util import u, unicode_type
 
 
@@ -37,6 +37,8 @@ class TranslationLoaderTest(unittest.TestCase):
         self.assertTrue(isinstance(locale, tornado.locale.CSVLocale))
         self.assertEqual(locale.translate("school"), u("\u00e9cole"))
 
+    # tempfile.mkdtemp is not available on app engine.
+    @skipOnAppEngine
     def test_csv_bom(self):
         with open(os.path.join(os.path.dirname(__file__), 'csv_translations',
                                'fr_FR.csv'), 'rb') as f:
diff --git a/tornado/test/util.py b/tornado/test/util.py
index b8feff4f..cfa7c81d 100644
--- a/tornado/test/util.py
+++ b/tornado/test/util.py
@@ -26,6 +26,9 @@ skipIfNonUnix = unittest.skipIf(os.name != 'posix' or sys.platform == 'cygwin',
 skipOnTravis = unittest.skipIf('TRAVIS' in os.environ,
                                'timing tests unreliable on travis')
 
+skipOnAppEngine = unittest.skipIf('APPENGINE_RUNTIME' in os.environ,
+                                  'not available on Google App Engine')
+
 # Set the environment variable NO_NETWORK=1 to disable any tests that
 # depend on an external network.
 skipIfNoNetwork = unittest.skipIf('NO_NETWORK' in os.environ,