diff --git a/app/package.json b/app/package.json
index 7019a5742d..fa4a6e6e3f 100644
--- a/app/package.json
+++ b/app/package.json
@@ -333,6 +333,7 @@
         "@jupyterlab/notebook-extension": [
           "@jupyterlab/notebook-extension:active-cell-tool",
           "@jupyterlab/notebook-extension:completer",
+          "@jupyterlab/notebook-extension:copy-output",
           "@jupyterlab/notebook-extension:metadata-editor",
           "@jupyterlab/notebook-extension:search",
           "@jupyterlab/notebook-extension:toc",