diff --git a/beembase/objects.py b/beembase/objects.py
index 2131fef85f4682cea5ec310e66a27ddd29bb9376..586eeb3f43ec250418a6bbe1a340130b7327cc59 100644
--- a/beembase/objects.py
+++ b/beembase/objects.py
@@ -363,7 +363,7 @@ class UpdateProposalExtensions(Static_variant):
             else:
                 type_id = ~0
         else:
-            type_id, data = o        
+            type_id, data = o
 
         if type_id == 1:
             data = (UpdateProposalEndDate(o['value']))
diff --git a/beembase/operations.py b/beembase/operations.py
index 41e40ab015a1fa548652b2459b90956ca679b14b..126024a93a997c8a6507d02ad81e2284d1dec18c 100644
--- a/beembase/operations.py
+++ b/beembase/operations.py
@@ -402,8 +402,9 @@ class Update_proposal(GrapheneObject):
 
         prefix = kwargs.get("prefix", default_prefix)
         extensions = Array([])
-        if "extensions" in kwargs and kwargs["extensions"]:
-            extensions = Array([UpdateProposalExtensions(o) for o in kwargs["extensions"]])
+        if "end_date" in kwargs and kwargs["end_date"]:
+            extension = { 'type': 'update_proposal_end_date', 'value': {'end_date': kwargs["end_date"]} }
+            extensions = Array([UpdateProposalExtensions(extension)])
 
 
         super(Update_proposal, self).__init__(