diff --git a/moulinette/authenticators/ldap.py b/moulinette/authenticators/ldap.py
index 53cd0899..5aff7ba4 100644
--- a/moulinette/authenticators/ldap.py
+++ b/moulinette/authenticators/ldap.py
@@ -59,6 +59,8 @@ class Authenticator(BaseAuthenticator):
 
     @property
     def is_authenticated(self):
+        if not self.con:
+            return False
         try:
             # Retrieve identity
             who = self.con.whoami_s()