diff --git a/welco/sources/phone/views.py b/welco/sources/phone/views.py
index f04341f..7f59ada 100644
--- a/welco/sources/phone/views.py
+++ b/welco/sources/phone/views.py
@@ -200,7 +200,7 @@ def take_line(request):
     try:
         payload = json.loads(request.body)
         assert isinstance(payload, dict), 'payload is not a JSON object'
-        assert payload.keys() == ['callee'], 'payload must have only one key: callee'
+        assert list(payload.keys()) == ['callee'], 'payload must have only one key: callee'
     except (TypeError, ValueError, AssertionError) as e:
         return HttpResponseBadRequest(json.dumps({'err': 1, 'msg':
                                                   force_text(e)}),
@@ -221,7 +221,7 @@ def release_line(request):
     try:
         payload = json.loads(request.body)
         assert isinstance(payload, dict), 'payload is not a JSON object'
-        assert payload.keys() == ['callee'], 'payload must have only one key: callee'
+        assert list(payload.keys()) == ['callee'], 'payload must have only one key: callee'
     except (TypeError, ValueError, AssertionError) as e:
         return HttpResponseBadRequest(json.dumps({'err': 1, 'msg':
                                                   force_text(e)}),