diff --git a/settings/templates/settings.development.notice.php b/settings/templates/settings.development.notice.php
index cbdd0e29fd6..86840677831 100644
--- a/settings/templates/settings.development.notice.php
+++ b/settings/templates/settings.development.notice.php
@@ -36,11 +36,11 @@
 				image_path('core', 'twitter.svg'),
 				image_path('core', 'rss.svg'),
 				image_path('core', 'mail.svg'),
-				'<a target="_blank" href="https://plus.google.com/b/104036748063781940910/104036748063781940910/about">',
-				'<a target="_blank" href="https://www.facebook.com/Nextcloud-1032807203462807/">',
-				'<a target="_blank" href="https://twitter.com/nextclouders">',
-				'<a target="_blank" href="https://nextcloud.com/blogfeed">',
-				'<a target="_blank" href="https://newsletter.nextcloud.com/?p=subscribe&amp;id=1">',
+				'<a target="_blank" rel="noreferrer noopener" href="https://plus.google.com/b/104036748063781940910/104036748063781940910/about">',
+				'<a target="_blank" rel="noreferrer noopener" href="https://www.facebook.com/Nextcloud-1032807203462807/">',
+				'<a target="_blank" rel="noreferrer noopener" href="https://twitter.com/nextclouders">',
+				'<a target="_blank" rel="noreferrer noopener" href="https://nextcloud.com/blogfeed">',
+				'<a target="_blank" rel="noreferrer noopener" href="https://newsletter.nextcloud.com/?p=subscribe&amp;id=1">',
 				'</a>',
 			],
 			$l->t('