opendj-server-legacy/src/main/java/org/opends/guitools/controlpanel/task/ModifyAttributeTask.java
@@ -167,7 +167,7 @@ Map<String, List<String>> extraProperties = DeleteSchemaElementsTask.cloneExtraProperties(ocToDelete); Set<AttributeType> required = new HashSet<>(ocToDelete.getDeclaredRequiredAttributes()); Set<AttributeType> optional = new HashSet<>(ocToDelete.getOptionalAttributes()); Set<AttributeType> optional = new HashSet<>(ocToDelete.getDeclaredOptionalAttributes()); if (required.contains(oldAttribute)) { required.remove(oldAttribute);