diff --git a/lib/6to5/transformers/classes.js b/lib/6to5/transformers/classes.js
index 9ac9aa3ced..0bb447bb12 100644
--- a/lib/6to5/transformers/classes.js
+++ b/lib/6to5/transformers/classes.js
@@ -3,14 +3,14 @@ var util     = require("../util");
 var b        = require("ast-types").builders;
 var _        = require("lodash");
 
-exports.ClassDeclaration = function (node) {
+exports.ClassDeclaration = function (node, parent, opts, generateUid) {
   return b.variableDeclaration("var", [
-    b.variableDeclarator(node.id, buildClass(node))
+    b.variableDeclarator(node.id, buildClass(node, generateUid))
   ]);
 };
 
-exports.ClassExpression = function (node) {
-  return buildClass(node);
+exports.ClassExpression = function (node, parent, opts, generateUid) {
+  return buildClass(node, generateUid);
 };
 
 var getMemberExpressionObject = function (node) {
@@ -20,14 +20,20 @@ var getMemberExpressionObject = function (node) {
   return node;
 };
 
-var buildClass = function (node) {
+var buildClass = function (node, generateUid) {
   var superName = node.superClass;
   var className = node.id || b.identifier("Anonymous");
 
-  var superClassReference = node.superClass;
+  var superClassArgument = node.superClass;
+  var superClassCallee   = node.superClass;
 
-  if (superName && superName.type === "MemberExpression") {
-    superClassReference = getMemberExpressionObject(superName);
+  if (superName) {
+    if (superName.type === "MemberExpression") {
+      superClassArgument = superClassCallee = getMemberExpressionObject(superName);
+    } else if (superName.type !== "Identifier") {
+      superClassArgument = superName;
+      superClassCallee = superName = b.identifier(generateUid("ref"));
+    }
   }
 
   var container = util.template("class", {
@@ -45,8 +51,8 @@ var buildClass = function (node) {
       CLASS_NAME: className
     }, true));
 
-    container.arguments.push(superClassReference);
-    container.callee.params.push(superClassReference);
+    container.arguments.push(superClassArgument);
+    container.callee.params.push(superClassCallee);
   }
 
   buildClassBody(body, className, superName, node);
diff --git a/package.json b/package.json
index 3084236f01..4cd0152638 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
   "name": "6to5",
   "description": "Turn ES6 code into vanilla ES5 with source maps and no runtime",
-  "version": "1.7.0",
+  "version": "1.7.1",
   "author": "Sebastian McKenzie <sebmck@gmail.com>",
   "homepage": "https://github.com/sebmck/6to5",
   "repository": {
diff --git a/test/fixtures/classes/super-class-non-identifiers/actual.js b/test/fixtures/classes/super-class-non-identifiers/actual.js
new file mode 100644
index 0000000000..61658914b7
--- /dev/null
+++ b/test/fixtures/classes/super-class-non-identifiers/actual.js
@@ -0,0 +1,3 @@
+class Q extends function() {} {
+  
+}
diff --git a/test/fixtures/classes/super-class-non-identifiers/expected.js b/test/fixtures/classes/super-class-non-identifiers/expected.js
new file mode 100644
index 0000000000..87b186465f
--- /dev/null
+++ b/test/fixtures/classes/super-class-non-identifiers/expected.js
@@ -0,0 +1,14 @@
+var Q = function(_ref) {
+  function Q() {}
+
+  Q.prototype = Object.create(_ref.prototype, {
+    constructor: {
+      value: Q,
+      enumerable: false,
+      writable: true,
+      configurable: true
+    }
+  });
+
+  return Q;
+}(function() {});