diff --git a/website/docs/guides/markdown-features/markdown-features-code-blocks.mdx b/website/docs/guides/markdown-features/markdown-features-code-blocks.mdx
index 7a2969ab23..4dc78ecb2e 100644
--- a/website/docs/guides/markdown-features/markdown-features-code-blocks.mdx
+++ b/website/docs/guides/markdown-features/markdown-features-code-blocks.mdx
@@ -81,6 +81,8 @@ module.exports = {
 };
 ```
 
+After adding `additionalLanguages`, restart Docusaurus.
+
 If you want to add highlighting for languages not yet supported by Prism, you can swizzle `prism-include-languages`:
 
 ```bash npm2yarn