diff --git a/doc/api/_toc.md b/doc/api/_toc.md
index 420fb362fa537a..b8002fb78163ac 100644
--- a/doc/api/_toc.md
+++ b/doc/api/_toc.md
@@ -1,5 +1,9 @@
 @// NB(chrisdickinson): if you move this file, be sure to update tools/doc/html.js to
 @// point at the new location.
+@// tools/doc/html.js to point at the new location.
+
+<!--introduced_in=v0.10.0-->
+
 * [About these Docs](documentation.html)
 * [Usage & Example](synopsis.html)