diff --git a/plupload.js b/plupload.js
index f8be4d1..cda096d 100644
--- a/plupload.js
+++ b/plupload.js
@@ -62,6 +62,13 @@ Drupal.behaviors.plupload = {
         // completed uploading.
         // @todo Implement a setting for whether the field is required, rather
         //   than assuming that all are.
+        if (uploader.files.length == 0 && !pluploadSettings.required) {
+          for (var attr in originalFormAttributes) {
+            $form.attr(attr, originalFormAttributes[attr]);
+          }
+          return;
+        }
+        
         if (uploader.files.length > 0 && uploader.total.uploaded == uploader.files.length) {
           // Plupload's html4 runtime has a bug where it changes the attributes
           // of the form to handle the file upload, but then fails to change