zip4j not overwriting existing file in zip Folder when addFile is used to add file with the same name

Zip4j is a great and fast library, i have liked using it in my project, thanks for the Good work Mr. Lingala. I need to add a file to an existing zipped file containing a file with the same name as the file to be added. Each time i get a corrupt final zip file. I only succeed when i remove the file from the zip first, using the remove() method. This slows my program a bit by a second or two, i want to save more time without using the remove method and re-insert the file directly. Thank you sir