diff --git a/modoboa/extensions/sievefilters/__init__.py b/modoboa/extensions/sievefilters/__init__.py
index 061a4b473..108784139 100644
--- a/modoboa/extensions/sievefilters/__init__.py
+++ b/modoboa/extensions/sievefilters/__init__.py
@@ -57,7 +57,7 @@ def menu(target, user):
          "img" : "icon-check"}
         ]
 
-@events.observe("Userlogout")
+@events.observe("UserLogout")
 def userlogout(request):
     from lib import SieveClient
 
diff --git a/modoboa/extensions/webmail/__init__.py b/modoboa/extensions/webmail/__init__.py
index 0dedc89f6..e9917770e 100644
--- a/modoboa/extensions/webmail/__init__.py
+++ b/modoboa/extensions/webmail/__init__.py
@@ -88,7 +88,7 @@ def menu(target, user):
          "url" : reverse("modoboa.extensions.webmail.views.index")},
         ]
 
-@events.observe("Userlogout")
+@events.observe("UserLogout")
 def userlogout(request):
     from lib import IMAPconnector