diff --git a/pkgs/by-name/ni/nixos-render-docs/src/nixos_render_docs/manual.py b/pkgs/by-name/ni/nixos-render-docs/src/nixos_render_docs/manual.py
index 9177b0ad5202..8e0f289f178f 100644
--- a/pkgs/by-name/ni/nixos-render-docs/src/nixos_render_docs/manual.py
+++ b/pkgs/by-name/ni/nixos-render-docs/src/nixos_render_docs/manual.py
@@ -375,6 +375,7 @@ class ManualHTMLRenderer(RendererMixin, HTMLRenderer):
         # Without this the popover can still be closed by clicking outside of it
         # It handles auto-closing when the user clicks a href.
         close_menu_js = """
+            //<![CDATA[
             document.addEventListener("DOMContentLoaded", () => {
                 const nav = document.getElementById("manual-toc");
                 nav?.addEventListener("click", (e) => {
@@ -383,6 +384,7 @@ class ManualHTMLRenderer(RendererMixin, HTMLRenderer):
                     }
                 });
             });
+            //]]>
         """
         header_content = ""
         if self._html_params.header: