diff --git a/lib/private/Files/Cache/CacheEntry.php b/lib/private/Files/Cache/CacheEntry.php
index 744b88b5b5..a0ba902090 100644
--- a/lib/private/Files/Cache/CacheEntry.php
+++ b/lib/private/Files/Cache/CacheEntry.php
@@ -27,7 +27,7 @@ use OCP\Files\Cache\ICacheEntry;
 /**
  * meta data for a file or folder
  */
-class CacheEntry implements ICacheEntry, \ArrayAccess {
+class CacheEntry implements ICacheEntry {
 	/**
 	 * @var array
 	 */
diff --git a/lib/public/Files/Cache/ICacheEntry.php b/lib/public/Files/Cache/ICacheEntry.php
index e3efe679cd..7a0e22496e 100644
--- a/lib/public/Files/Cache/ICacheEntry.php
+++ b/lib/public/Files/Cache/ICacheEntry.php
@@ -23,12 +23,18 @@
 
 namespace OCP\Files\Cache;
 
+use ArrayAccess;
+
 /**
  * meta data for a file or folder
  *
  * @since 9.0.0
+ *
+ * This interface extends \ArrayAccess since v21.0.0, previous versions only
+ * implemented it in the private implementation. Hence php would allow using the
+ * object as array, while strictly speaking it didn't support this.
  */
-interface ICacheEntry {
+interface ICacheEntry extends ArrayAccess {
 	public const DIRECTORY_MIMETYPE = 'httpd/unix-directory';
 
 	/**