diff --git a/ldapauthenticator/ldapauthenticator.py b/ldapauthenticator/ldapauthenticator.py
index f53da58..7f3eff4 100644
--- a/ldapauthenticator/ldapauthenticator.py
+++ b/ldapauthenticator/ldapauthenticator.py
@@ -343,7 +343,7 @@ def authenticate(self, handler, data):
                     exc_msg=exc.args[0] if exc.args else "",
                 )
             else:
-                is_bound = conn.bind()
+                is_bound = True if conn.bound else conn.bind()
             msg = msg.format(username=username, userdn=userdn, is_bound=is_bound)
             self.log.debug(msg)
             if is_bound: