diff --git a/apps/dav/lib/Upload/AssemblyStream.php b/apps/dav/lib/Upload/AssemblyStream.php
index 1a73669698b68..c3002e8458e4b 100644
--- a/apps/dav/lib/Upload/AssemblyStream.php
+++ b/apps/dav/lib/Upload/AssemblyStream.php
@@ -161,7 +161,9 @@ public function stream_truncate($size) {
 	 * @return array
 	 */
 	public function stream_stat() {
-		return [];
+		return [
+			'size' => $this->size,
+		];
 	}
 
 	/**