diff --git a/addons/mail/static/src/components/attachment_viewer/attachment_viewer.js b/addons/mail/static/src/components/attachment_viewer/attachment_viewer.js
index f079bf65c49..1642e531758 100644
--- a/addons/mail/static/src/components/attachment_viewer/attachment_viewer.js
+++ b/addons/mail/static/src/components/attachment_viewer/attachment_viewer.js
@@ -146,7 +146,7 @@ class AttachmentViewer extends Component {
      */
     _download() {
         const id = this.attachmentViewer.attachment.id;
-        this.env.services.navigate(`/web/content/ir.attachment/${id}/datas?download=true`);
+        this.env.services.navigate(`/web/content/ir.attachment/${id}/datas`, { download: true });
     }
 
     /**