diff --git a/consular/main.py b/consular/main.py
index 3f663d8..79c5569 100644
--- a/consular/main.py
+++ b/consular/main.py
@@ -135,7 +135,7 @@ def update_task_running(self, request, event):
 
     def update_task_killed(self, request, event):
         d = self.consul_request('PUT', '/v1/agent/service/deregister/%s' % (
-            get_appid(event),))
+            event['taskId'],))
         d.addCallback(lambda _: json.dumps({'status': 'ok'}))
         return d
 
diff --git a/consular/tests/test_main.py b/consular/tests/test_main.py
index 28f988a..62f2d97 100644
--- a/consular/tests/test_main.py
+++ b/consular/tests/test_main.py
@@ -141,7 +141,7 @@ def test_TASK_RUNNING(self):
         self.assertEqual(request['path'], '/v1/agent/service/register')
         self.assertEqual(request['data'], {
             'Name': 'my-app',
-            'taskId': 'my-app_0-1396592784349',
+            'ID': 'my-app_0-1396592784349',
             'Address': 'slave-1234.acme.org',
             'Port': 31372,
         })