diff --git a/public/js/mathjax-config-extra.js b/public/js/mathjax-config-extra.js
index 11ba59c600..f5dc895ed4 100644
--- a/public/js/mathjax-config-extra.js
+++ b/public/js/mathjax-config-extra.js
@@ -4,5 +4,8 @@ window.MathJax = {
   tex2jax: {
     inlineMath: [['$', '$'], ['\\(', '\\)']],
     processEscapes: true
+  },
+  TeX: {
+    extensions: ['mhchem.js']
   }
 }