diff --git a/lib/private/Files/Stream/Encryption.php b/lib/private/Files/Stream/Encryption.php
index 10df9ae98e2..0d55385820c 100644
--- a/lib/private/Files/Stream/Encryption.php
+++ b/lib/private/Files/Stream/Encryption.php
@@ -42,7 +42,7 @@ class Encryption extends Wrapper {
 	/**
 	 * user who perform the read/write operation null for public access
 	 */
-	protected string $uid;
+	protected ?string $uid;
 	protected bool $readOnly;
 	protected bool $writeFlag;
 	protected array $expectedContextProperties;