diff --git a/lib/ucoinpy/documents/certification.py b/lib/ucoinpy/documents/certification.py
index 79f6d11f04910153d1db8af8bbf7b9c46a6b2e9d..ce5eff0e6a9007b247231c8841e6b2ee8de9a81b 100644
--- a/lib/ucoinpy/documents/certification.py
+++ b/lib/ucoinpy/documents/certification.py
@@ -57,7 +57,7 @@ class Certification(Document):
     re_timestamp = re.compile("META:TS:([0-9]+)-([0-9a-fA-F]{5,40})\n")
 
     def __init__(self, version, currency, pubkey_from, pubkey_to,
-                 blockhash, blocknumber, signature):
+                 blocknumber, blockhash, signature):
         '''
         Constructor
         '''
diff --git a/src/cutecoin/core/account.py b/src/cutecoin/core/account.py
index 4fc001be71c80c95a02cca77d5bf0dec242e5af0..cfc93f61b0362543c003ab8ad2e4d79584e4b589 100644
--- a/src/cutecoin/core/account.py
+++ b/src/cutecoin/core/account.py
@@ -185,7 +185,9 @@ class Account(object):
                                     'other': []})
 
     def send_membership(self, password, community, type):
-        selfcert = Person.lookup(self.pubkey, community)
+        self_ = Person.lookup(self.pubkey, community)
+        selfcert = self_.selfcert(community)
+
         blockid = community.current_blockid()
 
         membership = Membership(PROTOCOL_VERSION, community.currency,
diff --git a/src/cutecoin/gui/community_tab.py b/src/cutecoin/gui/community_tab.py
index 153d0584328319a816fc9f5eee26bf6f122f2734..c6c792754ca94c097984dee06372dd1ff674a91c 100644
--- a/src/cutecoin/gui/community_tab.py
+++ b/src/cutecoin/gui/community_tab.py
@@ -102,6 +102,8 @@ class CommunityTabWidget(QWidget, Ui_CommunityTabWidget):
 
         try:
             self.account.send_membership(password, self.community, 'IN')
+            QMessageBox.information(self, "Membership",
+                                 "Success sending membership demand")
         except ValueError as e:
             QMessageBox.critical(self, "Join demand error",
                               str(e))
@@ -117,6 +119,8 @@ class CommunityTabWidget(QWidget, Ui_CommunityTabWidget):
 
         try:
             self.account.send_membership(password, self.community, 'OUT')
+            QMessageBox.information(self, "Membership",
+                                 "Success sending leaving demand")
         except ValueError as e:
             QMessageBox.critical(self, "Leaving demand error",
                               e.message)