diff --git a/development/jupyterlab_server/README b/development/jupyterlab_server/README
index 6659243304..79f8f7abb7 100644
--- a/development/jupyterlab_server/README
+++ b/development/jupyterlab_server/README
@@ -2,3 +2,6 @@ JupyterLab Server sits between JupyterLab and Jupyter Server, and
 provides a set of REST API handlers and utilities that are used by
 JupyterLab. It is a separate project in order to accommodate creating
 JupyterLab-like applications from a more limited scope.
+
+jupyterlab_server 2.16.3 is the last possible version for Slackware
+15.0. Newer versions would require a newer python-requests.