diff --git a/realms/modules/auth/ldap/models.py b/realms/modules/auth/ldap/models.py
index a3c7dd4..b230896 100644
--- a/realms/modules/auth/ldap/models.py
+++ b/realms/modules/auth/ldap/models.py
@@ -113,7 +113,7 @@ def start_tls(self):
                 return False
             try:
                 return self.conn.start_tls()
-            except ldap3.LDAPStartTLSError as ex:
+            except ldap3.core.exceptions.LDAPStartTLSError as ex:
                 logger.exception("START_TLS error")
                 return False
             except Exception as ex: