diff --git a/build b/build
index 50c073c..597846c 100755
--- a/build
+++ b/build
@@ -63,7 +63,7 @@ extract() {
 
     output "${subdirs##, })"$'\n'
 
-    if (echo "julia coffee-script elixir fish git plantuml scala swift jinja mdx" | grep -qF "$name"); then
+    if (echo "julia coffee-script elixir fish git plantuml scala swift jinja" | grep -qF "$name"); then
       echo "Skipping ftdetect installation of $name" >&2
       continue
     fi
diff --git a/config.vim b/config.vim
index 733e8b4..a141e59 100644
--- a/config.vim
+++ b/config.vim
@@ -72,9 +72,6 @@ augroup filetypedetect
   "jinja
   autocmd BufNewFile,BufRead *.jinja2,*.j2,*.jinja,*.nunjucks,*.nunjs,*.njk set ft=jinja
 
-  "mdx
-  autocmd BufNewFile,BufRead *.mdx set filetype=markdown.mdx
-
   "tsx
   autocmd BufNewFile,BufRead *.tsx setfiletype typescript.jsx
 augroup END
diff --git a/ftdetect/polyglot.vim b/ftdetect/polyglot.vim
index 9b91f84..2113780 100644
--- a/ftdetect/polyglot.vim
+++ b/ftdetect/polyglot.vim
@@ -72,9 +72,6 @@ augroup filetypedetect
   "jinja
   autocmd BufNewFile,BufRead *.jinja2,*.j2,*.jinja,*.nunjucks,*.nunjs,*.njk set ft=jinja
 
-  "mdx
-  autocmd BufNewFile,BufRead *.mdx set filetype=markdown.mdx
-
   "tsx
   autocmd BufNewFile,BufRead *.tsx setfiletype typescript.jsx
 augroup END
@@ -714,6 +711,19 @@ au BufRead,BufNewFile *.{md,mdown,mkd,mkdn,markdown,mdwn}.{des3,des,bf,bfa,aes,i
   augroup end
 endif
 
+if !exists('g:polyglot_disabled') || index(g:polyglot_disabled, 'mdx') == -1
+  augroup filetypedetect
+  " mdx, from mdx.vim in jxnblk/vim-mdx-js
+" Vim ftdetect file
+"
+" Language: MDX
+" Maintainer: Brent Jackson <jxnblk@gmail.com>
+"
+
+autocmd BufNewFile,BufRead *.mdx set filetype=markdown.mdx
+  augroup end
+endif
+
 if !exists('g:polyglot_disabled') || index(g:polyglot_disabled, 'meson') == -1
   augroup filetypedetect
   " meson, from meson.vim in mesonbuild/meson:_ALL:/data/syntax-highlighting/vim/