diff --git a/lib/ast.js b/lib/ast.js
index 2e539cff..1892a30a 100644
--- a/lib/ast.js
+++ b/lib/ast.js
@@ -359,9 +359,10 @@ var AST_Toplevel = DEFNODE("Toplevel", "globals", {
     }
 }, AST_Scope);
 
-var AST_Lambda = DEFNODE("Lambda", "name argnames uses_arguments", {
+var AST_Lambda = DEFNODE("Lambda", "name argnames uses_arguments isgenerator", {
     $documentation: "Base class for functions",
     $propdoc: {
+        isgenerator: "is generatorFn or not",
         name: "[AST_SymbolDeclaration?] the name of this function",
         argnames: "[AST_SymbolFunarg*] array of function arguments",
         uses_arguments: "[boolean/S] tells whether this function accesses the arguments array"
diff --git a/lib/output.js b/lib/output.js
index 135636b9..2a8cc201 100644
--- a/lib/output.js
+++ b/lib/output.js
@@ -220,6 +220,10 @@ function OutputStream(options) {
         might_need_space = true;
     };
 
+    var star = function(){
+        print("*");
+    }
+
     var indent = options.beautify ? function(half) {
         if (options.beautify) {
             print(make_indent(half ? 0.5 : 0));
@@ -332,6 +336,7 @@ function OutputStream(options) {
         newline         : newline,
         print           : print,
         space           : space,
+        star            : star,
         comma           : comma,
         colon           : colon,
         last            : function() { return last },
@@ -731,6 +736,8 @@ function OutputStream(options) {
         var self = this;
         if (!nokeyword) {
             output.print("function");
+            if(this.isgenerator)
+                output.star();
         }
         if (self.name) {
             output.space();
diff --git a/lib/parse.js b/lib/parse.js
index 95a9f776..f6ea9b40 100644
--- a/lib/parse.js
+++ b/lib/parse.js
@@ -953,12 +953,16 @@ function parse($TEXT, options) {
 
     var function_ = function(ctor) {
         var in_statement = ctor === AST_Defun;
+        var isgenerator = is("operator", "*");
+        if (isgenerator)
+            next();
         var name = is("name") ? as_symbol(in_statement ? AST_SymbolDefun : AST_SymbolLambda) : null;
         if (in_statement && !name)
             unexpected();
         expect("(");
         return new ctor({
             name: name,
+            isgenerator: isgenerator,
             argnames: (function(first, a){
                 while (!is("punc", ")")) {
                     if (first) first = false; else expect(",");