diff --git a/eventlet/websocket.py b/eventlet/websocket.py
index 20342db..1638199 100644
--- a/eventlet/websocket.py
+++ b/eventlet/websocket.py
@@ -101,7 +101,7 @@ class WebSocketWSGI(object):
             part.strip()
             for part in environ.get('HTTP_CONNECTION', '').lower().split(',')]
         if not ('upgrade' in http_connection_parts and
-                environ.get('HTTP_UPGRADE').lower() == 'websocket'):
+                environ.get('HTTP_UPGRADE', '').lower() == 'websocket'):
             # need to check a few more things here for true compliance
             start_response('400 Bad Request', [('Connection', 'close')])
             return []
diff --git a/tests/websocket_new_test.py b/tests/websocket_new_test.py
index 8a84895..629b28c 100644
--- a/tests/websocket_new_test.py
+++ b/tests/websocket_new_test.py
@@ -67,6 +67,21 @@ class TestWebSocket(_TestBase):
         self.assertEqual(resp.getheader('connection'), 'close')
         self.assertEqual(resp.read(), '')
 
+        # No Upgrade now
+        headers = dict(kv.split(': ') for kv in [
+                "Connection: Upgrade",
+                "Host: localhost:%s" % self.port,
+                "Origin: http://localhost:%s" % self.port,
+                "Sec-WebSocket-Version: 13", ])
+        http = httplib.HTTPConnection('localhost', self.port)
+        http.request("GET", "/echo", headers=headers)
+        resp = http.getresponse()
+
+        self.assertEqual(resp.status, 400)
+        self.assertEqual(resp.getheader('connection'), 'close')
+        self.assertEqual(resp.read(), '')
+
+
     def test_correct_upgrade_request_13(self):
         for http_connection in ['Upgrade', 'UpGrAdE', 'keep-alive, Upgrade']:
             connect = [