diff --git a/lib/private/Files/Cache/Wrapper/CacheJail.php b/lib/private/Files/Cache/Wrapper/CacheJail.php
index 37111206df0d4..8dc2ce14d3a21 100644
--- a/lib/private/Files/Cache/Wrapper/CacheJail.php
+++ b/lib/private/Files/Cache/Wrapper/CacheJail.php
@@ -311,6 +311,10 @@ public function getIncomplete() {
 	 */
 	public function getPathById($id) {
 		$path = $this->getCache()->getPathById($id);
+		if ($path === null) {
+			return null;
+		}
+
 		return $this->getJailedPath($path);
 	}