diff --git a/book/syntax_exercises/013.md b/book/syntax_exercises/013.md
index 1c501de..8fe41ba 100644
--- a/book/syntax_exercises/013.md
+++ b/book/syntax_exercises/013.md
@@ -45,8 +45,8 @@ You can generate BibTeX entries using free tools like [ZoteroBib](https://zbib.o
 * `{cite:ps}`
 * `{cite:ts}`
 
-```{hint} What to expect when you render these
-:class: dropdown
+```{admonition} What to expect when you render these
+:class: hint, dropdown
 Here’s how the citation will appear for the example in the shared bibliography:
 
 - `{cite:p}` → **Parenthetical citation**