diff --git a/web/sites/guides/astro.config.mjs b/web/sites/guides/astro.config.mjs
index c3ea1af170..07a536bae2 100644
--- a/web/sites/guides/astro.config.mjs
+++ b/web/sites/guides/astro.config.mjs
@@ -78,6 +78,12 @@ export default defineConfig({
 		// documented Phase 0 URLs are redirected.
 		'/v4-0-0-snapshot/cli-reference': '/v4-0-0-snapshot/command-line-tools/',
 		'/v4-0-0-snapshot/cli-reference/info': '/v4-0-0-snapshot/command-line-tools/',
+		// Astro/Starlight slugs the dotted filename `3.0.0-config-migration.md`
+		// down to `300-config-migration` (github-slugger strips dots). The file
+		// was renamed to `3-0-0-config-migration.md` so the URL matches every
+		// other doc in the tree; this redirect preserves the original ugly slug
+		// for any external bookmarks accumulated while it was live.
+		'/v3-0-0/upgrading/300-config-migration': '/v3-0-0/upgrading/3-0-0-config-migration/',
 	},
 	integrations: [
 		starlight({
diff --git a/web/sites/guides/src/content/docs/v3-0-0/upgrading/3.0.0-config-migration.md b/web/sites/guides/src/content/docs/v3-0-0/upgrading/3-0-0-config-migration.md
similarity index 100%
rename from web/sites/guides/src/content/docs/v3-0-0/upgrading/3.0.0-config-migration.md
rename to web/sites/guides/src/content/docs/v3-0-0/upgrading/3-0-0-config-migration.md
diff --git a/web/sites/guides/src/sidebars/v3-0-0.json b/web/sites/guides/src/sidebars/v3-0-0.json
index e746dab2be..df100aab03 100644
--- a/web/sites/guides/src/sidebars/v3-0-0.json
+++ b/web/sites/guides/src/sidebars/v3-0-0.json
@@ -42,7 +42,13 @@
       },
       {
         "label": "Upgrading",
-        "link": "/v3-0-0/introduction/upgrading/"
+        "link": "/v3-0-0/introduction/upgrading/",
+        "items": [
+          {
+            "label": "Config Directory Migration (3.0.0)",
+            "link": "/v3-0-0/upgrading/3-0-0-config-migration/"
+          }
+        ]
       },
       {
         "label": "Screencasts",