diff --git a/impacket/ldap/ldap.py b/impacket/ldap/ldap.py
index e8b6f75504..b34d5156e2 100644
--- a/impacket/ldap/ldap.py
+++ b/impacket/ldap/ldap.py
@@ -269,7 +269,9 @@ def kerberosLogin(self, user, password, domain='', lmhash='', nthash='', aesKey=
 
         # If TLS is used, setup channel binding
         
-        if self._SSL and self.__channel_binding_value is not None:
+        if self._SSL:
+            if self.__channel_binding_value is None:
+                self.__channel_binding_value = self.generateChannelBindingValue()
             chkField['Bnd'] = self.__channel_binding_value
         if self.__signing:
             chkField['Flags'] |= GSS_C_CONF_FLAG