diff --git a/lib/babel/transformation/transformers/es6/classes.js b/lib/babel/transformation/transformers/es6/classes.js
index 8ca8786924..c82d8566a0 100644
--- a/lib/babel/transformation/transformers/es6/classes.js
+++ b/lib/babel/transformation/transformers/es6/classes.js
@@ -65,6 +65,7 @@ function ClassTransformer(node, file, scope, isStatement) {
 ClassTransformer.prototype.run = function () {
   var superName = this.superName;
   var className = this.className;
+  var classBody = this.node.body.body;
   var file      = this.file;
 
   //
@@ -86,7 +87,10 @@ ClassTransformer.prototype.run = function () {
     var constructorName = null;
     // when class has no parent and there is only constructor or nothing then
     // constructor is not wrapped in closure and has to be named
-    if (!this.hasSuper && this.node.body.body.length <= 1) {
+    var containsOnlyConstructor = classBody.length === 1 &&
+                                  classBody[0].key.name === "constructor";
+    if (!this.hasSuper && (classBody.length === 0 ||
+                           containsOnlyConstructor)) {
       constructorName = className;
     }