diff --git a/lib/base.php b/lib/base.php
index 7d86245818df0..3619fa8f3b1c2 100644
--- a/lib/base.php
+++ b/lib/base.php
@@ -515,6 +515,8 @@ private static function performSameSiteCookieProtection() {
 		$incompatibleUserAgents = [
 			// OS X Finder
 			'/^WebDAVFS/',
+			// Sailfish caldav/carddav client
+			'/^Mozilla\/5\.0$/',
 		];
 		if($request->isUserAgent($incompatibleUserAgents)) {
 			return;