diff --git a/apps/files_external/lib/Command/Notify.php b/apps/files_external/lib/Command/Notify.php
index 04748117e278a7d90ca4ea7c0a4bf030d3c6a56e..b859a825c809d34c68d25dc25568a94a2b9e1b17 100644
--- a/apps/files_external/lib/Command/Notify.php
+++ b/apps/files_external/lib/Command/Notify.php
@@ -155,7 +155,7 @@ class Notify extends Base {
 	}
 
 	private function markParentAsOutdated($mountId, $path) {
-		$parent = dirname($path);
+		$parent = ltrim(dirname($path), '/');
 		if ($parent === '.') {
 			$parent = '';
 		}