diff --git a/js/script.js b/js/script.js
index 04878d2e9..06aebd909 100755
--- a/js/script.js
+++ b/js/script.js
@@ -253,7 +253,7 @@ $(function(){
 				for (var i = 0; i < activity.previews.length; i++) {
 					var preview = activity.previews[i];
 					content += ((preview.link) ? '<a href="' + preview.link + '">' + "\n" : '')
-						+ '<img class="preview' + ((preview.isMimeTypeIcon) ? ' preview-mimetype-icon' : '') + '" src="' + preview.source + '" alt="' + t('activity', 'Open file') + '" />' + "\n"
+						+ '<img class="preview' + ((preview.isMimeTypeIcon) ? ' preview-mimetype-icon' : '') + '" src="' + preview.source + '" alt="' + t('activity', 'Open {filename}', preview) + '" />' + "\n"
 						+ ((preview.link) ? '</a>' + "\n" : '')
 				}
 				content += '</div>';
diff --git a/lib/Controller/APIv2Controller.php b/lib/Controller/APIv2Controller.php
index faef30721..5f07116c9 100644
--- a/lib/Controller/APIv2Controller.php
+++ b/lib/Controller/APIv2Controller.php
@@ -363,6 +363,7 @@ protected function getPreview(string $owner, int $fileId, string $filePath): arr
 			'isMimeTypeIcon' => true,
 			'fileId' => $fileId,
 			'view' => $info['view'] ?: 'files',
+			'filename' => basename($filePath),
 		];
 
 		// show a preview image if the file still exists