diff --git a/unpacked/jax/input/TeX/config.js b/unpacked/jax/input/TeX/config.js
index 901d926e7..9727e1045 100644
--- a/unpacked/jax/input/TeX/config.js
+++ b/unpacked/jax/input/TeX/config.js
@@ -27,7 +27,7 @@
 
 MathJax.InputJax.TeX = MathJax.InputJax({
   id: "TeX",
-  version: "2.2",
+  version: "2.2.1",
   directory: MathJax.InputJax.directory + "/TeX",
   extensionDir: MathJax.InputJax.extensionDir + "/TeX",
   
diff --git a/unpacked/jax/input/TeX/jax.js b/unpacked/jax/input/TeX/jax.js
index f8fe94fcb..2e5320c8a 100644
--- a/unpacked/jax/input/TeX/jax.js
+++ b/unpacked/jax/input/TeX/jax.js
@@ -2127,9 +2127,9 @@
     mfenced: function (open,mml,close) {
       var mrow = MML.mrow();
       mrow.open = open; mrow.close = close;
-      if (open) {mrow.Append(MML.mo(open).With({fence:true, texClass:MML.TEXCLASS.OPEN}))}
+      if (open) {mrow.Append(MML.mo(open).With({fence:true, stretchy:true, texClass:MML.TEXCLASS.OPEN}))}
       if (mml.type === "mrow") {mrow.Append.apply(mrow,mml.data)} else {mrow.Append(mml)}
-      if (close) {mrow.Append(MML.mo(close).With({fence:true, texClass:MML.TEXCLASS.CLOSE}))}
+      if (close) {mrow.Append(MML.mo(close).With({fence:true, stretchy:true, texClass:MML.TEXCLASS.CLOSE}))}
       return mrow;
     },