diff --git a/src/display/annotation_layer.js b/src/display/annotation_layer.js
index 4d862e6c951a0..cfa4d840ef1d0 100644
--- a/src/display/annotation_layer.js
+++ b/src/display/annotation_layer.js
@@ -2890,7 +2890,7 @@ class FileAttachmentAnnotationElement extends AnnotationElement {
  * @property {Array} annotations
  * @property {PDFPageProxy} page
  * @property {IPDFLinkService} linkService
- * @property {IDownloadManager} downloadManager
+ * @property {IDownloadManager} [downloadManager]
  * @property {AnnotationStorage} [annotationStorage]
  * @property {string} [imageResourcesPath] - Path for image resources, mainly
  *   for annotation icons. Include trailing slash.