diff --git a/javascript/GridFieldBulkImageUpload.js b/javascript/GridFieldBulkImageUpload.js
index 3543efc..eca48e9 100644
--- a/javascript/GridFieldBulkImageUpload.js
+++ b/javascript/GridFieldBulkImageUpload.js
@@ -89,6 +89,7 @@
             if ( url.indexOf('?') !== -1 ) cacheBuster = '&cacheBuster=' + cacheBuster;
             else cacheBuster = '?cacheBuster=' + cacheBuster;
             
+            $(this).trigger('beforesubmitform');
             data = $(this).serialize();
 
 						$.ajax({
@@ -183,4 +184,4 @@
 		});
 	});
 
-}(jQuery));
\ No newline at end of file
+}(jQuery));