diff --git a/app/models/auth_source_ldap.rb b/app/models/auth_source_ldap.rb
index 3c55bff75..a1739c00e 100644
--- a/app/models/auth_source_ldap.rb
+++ b/app/models/auth_source_ldap.rb
@@ -250,4 +250,5 @@ class AuthSourceLdap < AuthSource
       value.to_s.force_encoding('UTF-8')
     end
   end
+  private_class_method :get_attr
 end