diff --git a/autopush/router/apns2.py b/autopush/router/apns2.py
index 85905f1f..1ccae889 100644
--- a/autopush/router/apns2.py
+++ b/autopush/router/apns2.py
@@ -11,8 +11,8 @@
 SANDBOX = 'api.development.push.apple.com'
 SERVER = 'api.push.apple.com'
 
-APNS_PRIORITY_IMMEDIATE = 10
-APNS_PRIORITY_LOW = 5
+APNS_PRIORITY_IMMEDIATE = '10'
+APNS_PRIORITY_LOW = '5'
 APNS_MAX_CONNECTIONS = 20
 
 
@@ -101,13 +101,14 @@ def send(self, router_token, payload, apns_id,
         """
         body = json.dumps(payload)
         priority = APNS_PRIORITY_IMMEDIATE if priority else APNS_PRIORITY_LOW
+        # NOTE: Hyper requires that all header values be strings.
         headers = {
             'apns-id': apns_id,
-            'apns-priority': priority,
+            'apns-priority': str(priority),
             'apns-topic': topic or self.topic,
         }
         if exp:
-            headers['apns-expiration'] = exp
+            headers['apns-expiration'] = str(exp)
         url = '/3/device/' + router_token
         connection = self._get_connection()
         try:
diff --git a/autopush/tests/test_router.py b/autopush/tests/test_router.py
index d7f65e39..dce99fea 100644
--- a/autopush/tests/test_router.py
+++ b/autopush/tests/test_router.py
@@ -200,9 +200,9 @@ def test_route_low_priority_notification(self):
         ok_(self.mock_connection.request.called)
         body = self.mock_connection.request.call_args[1]
         headers = body['headers']
-        eq_(headers, {'apns-expiration': exp,
+        eq_(headers, {'apns-expiration': str(exp),
                       'apns-topic': 'com.example.SomeApp',
-                      'apns-priority': 5,
+                      'apns-priority': '5',
                       'apns-id': 'apnsid'})
 
     @inlineCallbacks