diff --git a/themes/default/public/js/upload.js b/themes/default/public/js/upload.js
index e223cad..4693491 100644
--- a/themes/default/public/js/upload.js
+++ b/themes/default/public/js/upload.js
@@ -499,8 +499,9 @@ document.addEventListener("DOMContentLoaded", () => {
       : "";
 
     const zipMultiple = document.getElementById("zip-multiple").checked;
-    const zipName = document.querySelector("#zip-name input").value;
-
+    let zipName = document.querySelector("#zip-name input").value;
+    zipName = zipName.endsWith(".zip") ? zipName : `${zipName}.zip`;
+    
     const mustZip = providedFiles.length > 1 ? zipMultiple : false;
 
     startUpload(