diff --git a/autopush/router/webpush.py b/autopush/router/webpush.py
index c29a9a22..26401574 100644
--- a/autopush/router/webpush.py
+++ b/autopush/router/webpush.py
@@ -70,6 +70,9 @@ def preflight_check(self, uaid, channel_id):
                                   log_exception=False, errno=106)
 
         month_table = record["current_month"]
+        if month_table not in self.ap_settings.message_tables:
+            raise RouterException("No such subscription", status_code=404,
+                                  log_exception=False, errno=106)
         exists, chans = yield deferToThread(
             self.ap_settings.message_tables[month_table].all_channels,
             uaid=uaid)
diff --git a/autopush/tests/test_router.py b/autopush/tests/test_router.py
index d9a4f137..42e97a17 100644
--- a/autopush/tests/test_router.py
+++ b/autopush/tests/test_router.py
@@ -757,6 +757,28 @@ def verify_deliver(fail):
         d.addBoth(verify_deliver)
         return d
 
+    def test_route_with_missing_month(self):
+        self.agent_mock.request.return_value = response_mock = Mock()
+        response_mock.addCallback.return_value = response_mock
+        type(response_mock).code = PropertyMock(
+            side_effect=MockAssist([202, 200]))
+        self.message_mock.store_message.return_value = True
+        self.message_mock.all_channels.return_value = (True, [])
+        router_data = dict(node_id="http://somewhere",
+                           uaid=dummy_uaid)
+        self.router_mock.get_uaid.return_value = router_data
+        self.router.message_id = uuid.uuid4().hex
+
+        d = self.router.route_notification(self.notif, router_data)
+
+        def verify_deliver(fail):
+            exc = fail.value
+            ok_(exc, RouterException)
+            eq_(exc.status_code, 404)
+            self.flushLoggedErrors()
+        d.addBoth(verify_deliver)
+        return d
+
     def test_route_with_invalid_channel_id(self):
         self.agent_mock.request.return_value = response_mock = Mock()
         response_mock.addCallback.return_value = response_mock
@@ -764,7 +786,33 @@ def test_route_with_invalid_channel_id(self):
             side_effect=MockAssist([202, 200]))
         self.message_mock.store_message.return_value = True
         self.message_mock.all_channels.return_value = (True, [])
-        router_data = dict(node_id="http://somewhere", uaid=dummy_uaid)
+        month = self.router.ap_settings.current_msg_month
+        router_data = dict(node_id="http://somewhere",
+                           current_month=month,
+                           uaid=dummy_uaid)
+        self.router_mock.get_uaid.return_value = router_data
+        self.router.message_id = uuid.uuid4().hex
+
+        d = self.router.route_notification(self.notif, router_data)
+
+        def verify_deliver(fail):
+            exc = fail.value
+            ok_(exc, RouterException)
+            eq_(exc.status_code, 404)
+            self.flushLoggedErrors()
+        d.addBoth(verify_deliver)
+        return d
+
+    def test_route_with_invalid_month(self):
+        self.agent_mock.request.return_value = response_mock = Mock()
+        response_mock.addCallback.return_value = response_mock
+        type(response_mock).code = PropertyMock(
+            side_effect=MockAssist([202, 200]))
+        self.message_mock.store_message.return_value = True
+        self.message_mock.all_channels.return_value = (True, [])
+        router_data = dict(node_id="http://somewhere",
+                           current_month="invalid_month",
+                           uaid=dummy_uaid)
         self.router_mock.get_uaid.return_value = router_data
         self.router.message_id = uuid.uuid4().hex