diff --git a/webinstaller/app.py b/webinstaller/app.py
index 306ecfe..f7722ee 100644
--- a/webinstaller/app.py
+++ b/webinstaller/app.py
@@ -632,8 +632,11 @@ def install_reboot():
     log = INSTALL_LOG.read_text() if INSTALL_LOG.exists() else ""
     if parse_install_progress(log)["status"] != "done":
         return redirect(url_for("install_log_view"))
+    # Delay reboot a few seconds so the browser can finish fetching CSS / assets
+    # for the rebooting page before the Flask server (and network) go away.
+    # Without this, the reboot page renders unstyled (giant inline SVG icon).
     subprocess.Popen(
-        ["/usr/bin/systemctl", "reboot"],
+        ["/bin/sh", "-c", "sleep 3 && /usr/bin/systemctl reboot"],
         start_new_session=True,
     )
     return render_template("install/rebooting.html")