diff --git a/src/cutecoin/core/graph.py b/src/cutecoin/core/graph.py
index c46cf51f1dd3929dfecb416f3788dbbc672b3677..32db6b8d7df4f222b4180e38761e246cc4827acf 100644
--- a/src/cutecoin/core/graph.py
+++ b/src/cutecoin/core/graph.py
@@ -200,7 +200,8 @@ class Graph(object):
                 current_validations = self.community.network.latest_block_number - certifier['block_number']
             else:
                 current_validations = 0
-            max_validation = self.community.network.fork_window(self.community.members_pubkeys()) + 1
+            members_pubkeys = yield from self.community.members_pubkeys()
+            max_validation = self.community.network.fork_window(members_pubkeys) + 1
 
             # Current validation can be negative if self.community.network.latest_block_number
             # is not refreshed yet
diff --git a/src/cutecoin/core/registry/identity.py b/src/cutecoin/core/registry/identity.py
index 316af79561fa27086f14cc3d811e5333197b5aaf..10daff2398d36ec07f74b5f88c60b486549be9de 100644
--- a/src/cutecoin/core/registry/identity.py
+++ b/src/cutecoin/core/registry/identity.py
@@ -347,8 +347,9 @@ class Identity(QObject):
     def membership_expiration_time(self, community):
         membership = yield from self.membership(community)
         join_block = membership['blockNumber']
-        join_date = community.get_block(join_block)['medianTime']
-        parameters = community.parameters
+        block = yield from community.get_block(join_block)
+        join_date = block['medianTime']
+        parameters = yield from community.parameters()
         expiration_date = join_date + parameters['sigValidity']
         current_time = time.time()
         return expiration_date - current_time
diff --git a/src/cutecoin/gui/community_view.py b/src/cutecoin/gui/community_view.py
index da449122a17247ee7d8161647ab2df6ac2900336..c0e515d532d1436164047a50b24cbd732295fa81 100644
--- a/src/cutecoin/gui/community_view.py
+++ b/src/cutecoin/gui/community_view.py
@@ -130,7 +130,8 @@ class CommunityWidget(QWidget, Ui_CommunityWidget):
         try:
             person = yield from self.app.identities_registry.future_find(self.app.current_account.pubkey, self.community)
             expiration_time = yield from person.membership_expiration_time(self.community)
-            sig_validity = self.community.parameters['sigValidity']
+            parameters = yield from self.community.parameters()
+            sig_validity = parameters['sigValidity']
             warning_expiration_time = int(sig_validity / 3)
             will_expire_soon = (expiration_time < warning_expiration_time)
 
@@ -146,13 +147,13 @@ class CommunityWidget(QWidget, Ui_CommunityWidget):
 
             certifiers_of = yield from person.unique_valid_certifiers_of(self.app.identities_registry,
                                                                          self.community)
-            if len(certifiers_of) < self.community.parameters['sigQty']:
+            if len(certifiers_of) < parameters['sigQty']:
                 self.status_info.append('warning_certifications')
                 if self.app.preferences['notifications']:
                     toast.display(self.tr("Certifications number"),
                               self.tr("<b>Warning : You are certified by only {0} persons, need {1}</b>")
                               .format(len(certifiers_of),
-                                     self.community.parameters['sigQty']))
+                                     parameters['sigQty']))
 
         except MembershipNotFoundError as e:
             pass