diff --git a/.markdownlint-cli2.jsonc b/.markdownlint-cli2.jsonc
index 47b0a6ae6..3f340fbc2 100644
--- a/.markdownlint-cli2.jsonc
+++ b/.markdownlint-cli2.jsonc
@@ -23,6 +23,8 @@
     "MD024": { "siblings_only": true },
     // Bare URLs are fine in changelogs and tables.
     "MD034": false,
+    // Internal docs commonly use bare fences for diagrams and terminal sketches.
+    "MD040": false,
     // First line does not need to be a heading.
     "MD002": false,
     // Repo uses padded table pipes (`| foo | bar |`); rule default is "compact".
diff --git a/docs/.markdownlint-cli2.jsonc b/docs/.markdownlint-cli2.jsonc
index 6e86e6286..04cfcf7e2 100644
--- a/docs/.markdownlint-cli2.jsonc
+++ b/docs/.markdownlint-cli2.jsonc
@@ -3,6 +3,8 @@
     // MDX pages get their title from Fern frontmatter, not a top-level H1.
     "MD041": false,
     // MDX uses JSX components (<Callout>, <CodeBlock>, ...) that look like HTML.
-    "MD033": false
+    "MD033": false,
+    // Published docs should label fenced code blocks for rendering and copy UX.
+    "MD040": true
   }
 }