diff --git a/docs/mathjax-config.js b/docs/mathjax-config.js
index bec7b17..7b0ebca 100644
--- a/docs/mathjax-config.js
+++ b/docs/mathjax-config.js
@@ -1,5 +1,9 @@
 MathJax.Hub.Config({
   config: ["MMLorHTML.js"],
   jax: ["input/TeX", "output/HTML-CSS", "output/NativeMML"],
-  extensions: ["MathMenu.js", "MathZoom.js"]
+  extensions: ["MathMenu.js", "MathZoom.js"],
+  TeX: {
+    extensions: ["mhchem.js"],
+    mhchem: {legacy: false}
+  }
 });