diff --git a/src/Bundle/ChillWopiBundle/src/Service/Wopi/ChillDocumentManager.php b/src/Bundle/ChillWopiBundle/src/Service/Wopi/ChillDocumentManager.php
index 1924edd01..73a4dd285 100644
--- a/src/Bundle/ChillWopiBundle/src/Service/Wopi/ChillDocumentManager.php
+++ b/src/Bundle/ChillWopiBundle/src/Service/Wopi/ChillDocumentManager.php
@@ -190,7 +190,7 @@ final class ChillDocumentManager implements DocumentManagerInterface
     }
 
     public function getSize(Document $document): int {
-        return strlen(stream_get_contents($this->read($document)));
+        return strlen($this->read($document)->getContents());
     }
 
     public function read(Document $document): StreamInterface {