diff --git a/packages/tailwindcss-intellisense/src/lib/languages.ts b/packages/tailwindcss-intellisense/src/lib/languages.ts
index 0b9c450..af134ce 100644
--- a/packages/tailwindcss-intellisense/src/lib/languages.ts
+++ b/packages/tailwindcss-intellisense/src/lib/languages.ts
@@ -19,6 +19,7 @@ export const DEFAULT_LANGUAGES = [
   'leaf',
   'liquid',
   'markdown',
+  'mdx',
   'mustache',
   'njk',
   'nunjucks',
diff --git a/packages/tailwindcss-language-service/src/util/html.ts b/packages/tailwindcss-language-service/src/util/html.ts
index e82cf10..5f9a1ca 100644
--- a/packages/tailwindcss-language-service/src/util/html.ts
+++ b/packages/tailwindcss-language-service/src/util/html.ts
@@ -21,6 +21,7 @@ export const HTML_LANGUAGES = [
   'leaf',
   'liquid',
   'markdown',
+  'mdx',
   'mustache',
   'njk',
   'nunjucks',