diff --git a/crates/directory/src/backend/ldap/config.rs b/crates/directory/src/backend/ldap/config.rs
index 41a6c73d..54b9bab8 100644
--- a/crates/directory/src/backend/ldap/config.rs
+++ b/crates/directory/src/backend/ldap/config.rs
@@ -98,12 +98,15 @@ impl LdapDirectory {
             &mappings.attr_type,
             &mappings.attr_description,
             &mappings.attr_secret,
+            &mappings.attr_secret_changed,
             &mappings.attr_quota,
             &mappings.attr_groups,
             &mappings.attr_email_address,
             &mappings.attr_email_alias,
         ] {
-            mappings.attrs_principal.extend(attr.iter().cloned());
+            mappings
+                .attrs_principal
+                .extend(attr.iter().filter(|a| !a.is_empty()).cloned());
         }
 
         let auth_bind = match config