diff --git a/beat/web/attestations/api.py b/beat/web/attestations/api.py
index 8a3139cf0bdcb0d390ed5f740c94fa74df6b0733..279745695512ebbe81e4d17574ad60652f0214dc 100644
--- a/beat/web/attestations/api.py
+++ b/beat/web/attestations/api.py
@@ -65,7 +65,7 @@ class CreateAttestationView(APIView):
     def post(self, request):
         data = request.data
 
-        if not(data.has_key('experiment')):
+        if 'experiment' not in data:
             return BadRequestResponse('Missing field: experiment')
 
         if not(isinstance(data['experiment'], six.string_types)):
@@ -176,7 +176,7 @@ class UnlockAttestationView(APIView):
     def post(self, request, number):
         data = request.data
 
-        if data.has_key('visible_algorithms'):
+        if 'visible_algorithms' in data:
             if not(isinstance(data['visible_algorithms'], list)):
                 return BadRequestResponse('Invalid visible_algorithms data')