diff --git a/book/exercises/005a.md b/book/exercises/005a.md
index 6a21222..588b0f2 100644
--- a/book/exercises/005a.md
+++ b/book/exercises/005a.md
@@ -29,19 +29,19 @@ Can you include a page from someone else’s book into your own using `external:
 
 3. Save the changes, commit, and push them.
 
-```{admonition} Example: `_toc.yml` snippet
 
-```yaml
-format: jb-book
-root: intro
+````{admonition} Example: `_toc.yml` snippet
 
-chapters:
-  - file: 001
-  - external: https://github.com/TeachBooks/manual/blob/v1.1.1/book/examples/book_structure.md
-  - file: 003
-```
+  ```yaml
+  format: jb-book
+  root: intro
 
-```
+  chapters:
+    - file: 001
+    - external: https://github.com/TeachBooks/manual/blob/v1.1.1/book/examples/book_structure.md
+    - file: 003
+  ```
+````
 
 4. When you are ready, commit your changes to the repository by clicking on the green `Commit changes` button.