diff --git a/Slakefile b/Slakefile
index facec06f0..3afa5ad99 100644
--- a/Slakefile
+++ b/Slakefile
@@ -138,7 +138,13 @@ function runTests global.LiveScript
     else tint message
     if failedTests
       process.exit 1
-  dir(\test)forEach (file) ->
+  
+  files = dir \test
+  unless '--harmony' in process.execArgv or '--harmony-generators' in process.execArgv
+    say "Skipping --harmony tests"
+    files.splice (files.indexOf 'generators.ls'), 1
+
+  files.forEach (file) ->
     return unless /\.ls$/i.test file
     code = slurp filename = path.join \test file
     try LiveScript.run code, {filename} catch
diff --git a/lib/ast.js b/lib/ast.js
index a5ae7b7fe..459d58156 100644
--- a/lib/ast.js
+++ b/lib/ast.js
@@ -1660,7 +1660,10 @@ exports.Unary = Unary = (function(superclass){
     if (this.post) {
       code += op;
     } else {
-      if ((op === 'new' || op === 'typeof' || op === 'delete') || (op === '+' || op === '-') && op === code.charAt()) {
+      if (op === 'yieldfrom') {
+        op = 'yield* ';
+      }
+      if ((op === 'new' || op === 'typeof' || op === 'delete' || op === 'yield') || (op === '+' || op === '-') && op === code.charAt()) {
         op += ' ';
       }
       code = op + code;
@@ -2568,13 +2571,14 @@ exports.Existence = Existence = (function(superclass){
 }(Node, Negatable));
 exports.Fun = Fun = (function(superclass){
   var prototype = extend$((import$(Fun, superclass).displayName = 'Fun', Fun), superclass).prototype, constructor = Fun;
-  function Fun(params, body, bound, curried, hushed){
+  function Fun(params, body, bound, curried, hushed, generator){
     var this$ = this instanceof ctor$ ? this : new ctor$;
     this$.params = params || [];
     this$.body = body || Block();
     this$.bound = bound && 'this$';
     this$.curried = curried || false;
     this$.hushed = hushed != null ? hushed : false;
+    this$.generator = generator != null ? generator : false;
     return this$;
   } function ctor$(){} ctor$.prototype = prototype;
   prototype.children = ['params', 'body'];
@@ -2622,6 +2626,11 @@ exports.Fun = Fun = (function(superclass){
     o.indent += TAB;
     body = this.body, name = this.name, tab = this.tab;
     code = 'function';
+    if (this.generator) {
+      this.ctor && this.carp("a constructor can't be a generator");
+      this.hushed && this.carp("a generator is hushed by default");
+      code += '*';
+    }
     if (this.bound === 'this$') {
       if (this.ctor) {
         scope.assign('this$', 'this instanceof ctor$ ? this : new ctor$');
@@ -2641,7 +2650,7 @@ exports.Fun = Fun = (function(superclass){
     if (this.statement || name && this.labeled) {
       code += ' ' + scope.add(name, 'function', this);
     }
-    this.hushed || this.ctor || this.newed || body.makeReturn();
+    this.hushed || this.ctor || this.newed || this.generator || body.makeReturn();
     code += "(" + this.compileParams(o, scope) + "){";
     if (that = body.compileWithDeclarations(o)) {
       code += "\n" + that + "\n" + tab;
diff --git a/lib/grammar.js b/lib/grammar.js
index 1cfb42131..e303a1085 100644
--- a/lib/grammar.js
+++ b/lib/grammar.js
@@ -241,7 +241,7 @@ bnf = {
     }), o('Chain !?', function(){
       return Existence($1.unwrap(), true);
     }), o('PARAM( ArgList OptComma )PARAM -> Block', function(){
-      return L(Fun($2, $6, /~/.test($5), /--|~~/.test($5), /!/.test($5)));
+      return L(Fun($2, $6, /~/.test($5), /--|~~/.test($5), /!/.test($5), /\*/.test($5)));
     }), o('FUNCTION CALL( ArgList OptComma )CALL Block', function(){
       return L(Fun($3, $6).named($1));
     }), o('IF Expression Block Else', function(){
diff --git a/lib/lexer.js b/lib/lexer.js
index 257643071..1188a1d63 100644
--- a/lib/lexer.js
+++ b/lib/lexer.js
@@ -144,6 +144,7 @@ exports.doID = function(code, index){
   case 'do':
   case 'typeof':
   case 'delete':
+  case 'yield':
     tag = 'UNARY';
     break;
   case 'return':
@@ -312,6 +313,10 @@ exports.doID = function(code, index){
       }
       break;
     case 'from':
+      if (last[1] === 'yield') {
+        last[1] += 'from';
+        return 4;
+      }
       this.forange() && (tag = 'FROM');
       break;
     case 'to':
@@ -830,6 +835,12 @@ exports.doLiteral = function(code, index){
     this.token('IMPORT', '<<');
     return sym.length;
   case '*':
+    if (this.last[0] === '->') {
+      if (this.last[0] === '->') {
+        this.last[1] += '*';
+      }
+      return 1;
+    }
     if (that = ((ref$ = this.last[0]) === 'NEWLINE' || ref$ === 'INDENT' || ref$ === 'THEN' || ref$ === '=>') && (INLINEDENT.lastIndex = index + 1, INLINEDENT).exec(code)[0].length) {
       this.tokens.push(['LITERAL', 'void', this.line], ['ASSIGN', '=', this.line]);
       this.indent(index + that - 1 - this.dent - code.lastIndexOf('\n', index - 1));
@@ -1772,8 +1783,8 @@ function indexOfPair(tokens, i){
   }
   return -1;
 }
-KEYWORDS_SHARED = ['true', 'false', 'null', 'this', 'void', 'super', 'return', 'throw', 'break', 'continue', 'if', 'else', 'for', 'while', 'switch', 'case', 'default', 'try', 'catch', 'finally', 'function', 'class', 'extends', 'implements', 'new', 'do', 'delete', 'typeof', 'in', 'instanceof', 'let', 'with', 'var', 'const', 'import', 'export', 'debugger'];
-KEYWORDS_UNUSED = ['enum', 'interface', 'package', 'private', 'protected', 'public', 'static', 'yield'];
+KEYWORDS_SHARED = ['true', 'false', 'null', 'this', 'void', 'super', 'return', 'throw', 'break', 'continue', 'if', 'else', 'for', 'while', 'switch', 'case', 'default', 'try', 'catch', 'finally', 'function', 'class', 'extends', 'implements', 'new', 'do', 'delete', 'typeof', 'in', 'instanceof', 'let', 'with', 'var', 'const', 'import', 'export', 'debugger', 'yield'];
+KEYWORDS_UNUSED = ['enum', 'interface', 'package', 'private', 'protected', 'public', 'static'];
 JS_KEYWORDS = KEYWORDS_SHARED.concat(KEYWORDS_UNUSED);
 LS_KEYWORDS = ['xor', 'match', 'where'];
 ID = /((?!\s)[a-z_$\xAA-\uFFDC](?:(?!\s)[\w$\xAA-\uFFDC]|-[a-z])*)([^\n\S]*:(?![:=]))?|/ig;
diff --git a/lib/parser.js b/lib/parser.js
index b88182636..69264c9ef 100644
--- a/lib/parser.js
+++ b/lib/parser.js
@@ -3,7 +3,8 @@ yy: {},
 symbols_: {"error":2,"Chain":3,"ID":4,"Parenthetical":5,"List":6,"STRNUM":7,"LITERAL":8,"DOT":9,"Key":10,"CALL(":11,"ArgList":12,"OptComma":13,")CALL":14,"?":15,"LET":16,"Block":17,"[":18,"Expression":19,"LoopHeads":20,"]":21,"DEDENT":22,"{":23,"}":24,"(":25,"BIOP":26,")":27,"BIOPR":28,"BIOPBP":29,"BIOPP":30,"PARAM(":31,")PARAM":32,"UNARY":33,"CREMENT":34,"BACKTICK":35,"TO":36,"BY":37,"WITH":38,"FOR":39,"Properties":40,"LABEL":41,"KeyBase":42,"Arg":43,",":44,"NEWLINE":45,"INDENT":46,"...":47,"Lines":48,"Line":49,"<-":50,"COMMENT":51,"REQUIRE":52,"CLONEPORT":53,"ASSIGN":54,"IMPORT":55,"+-":56,"CLONE":57,"COMPARE":58,"LOGIC":59,"MATH":60,"POWER":61,"SHIFT":62,"BITWISE":63,"CONCAT":64,"COMPOSE":65,"RELATION":66,"PIPE":67,"BACKPIPE":68,"!?":69,"->":70,"FUNCTION":71,"IF":72,"Else":73,"POST_IF":74,"LoopHead":75,"DO":76,"WHILE":77,"CASE":78,"HURL":79,"JUMP":80,"SWITCH":81,"Exprs":82,"Cases":83,"DEFAULT":84,"ELSE":85,"TRY":86,"CATCH":87,"FINALLY":88,"CLASS":89,"OptExtends":90,"OptImplements":91,"EXTENDS":92,"DECL":93,"KeyValue":94,"Property":95,":":96,"Body":97,"IN":98,"OF":99,"FROM":100,"IMPLEMENTS":101,"Root":102,"$accept":0,"$end":1},
 terminals_: {2:"error",4:"ID",7:"STRNUM",8:"LITERAL",9:"DOT",11:"CALL(",14:")CALL",15:"?",16:"LET",18:"[",21:"]",22:"DEDENT",23:"{",24:"}",25:"(",26:"BIOP",27:")",28:"BIOPR",29:"BIOPBP",30:"BIOPP",31:"PARAM(",32:")PARAM",33:"UNARY",34:"CREMENT",35:"BACKTICK",36:"TO",37:"BY",38:"WITH",39:"FOR",41:"LABEL",44:",",45:"NEWLINE",46:"INDENT",47:"...",50:"<-",51:"COMMENT",52:"REQUIRE",53:"CLONEPORT",54:"ASSIGN",55:"IMPORT",56:"+-",57:"CLONE",58:"COMPARE",59:"LOGIC",60:"MATH",61:"POWER",62:"SHIFT",63:"BITWISE",64:"CONCAT",65:"COMPOSE",66:"RELATION",67:"PIPE",68:"BACKPIPE",69:"!?",70:"->",71:"FUNCTION",72:"IF",74:"POST_IF",76:"DO",77:"WHILE",78:"CASE",79:"HURL",80:"JUMP",81:"SWITCH",84:"DEFAULT",85:"ELSE",86:"TRY",87:"CATCH",88:"FINALLY",89:"CLASS",92:"EXTENDS",93:"DECL",96:":",98:"IN",99:"OF",100:"FROM",101:"IMPLEMENTS"},
 productions_: [0,[3,1],[3,1],[3,1],[3,1],[3,1],[3,3],[3,3],[3,5],[3,2],[3,6],[3,4],[3,5],[3,7],[3,3],[3,4],[3,4],[3,3],[3,4],[3,4],[3,3],[3,7],[3,3],[3,7],[3,3],[3,3],[3,5],[3,6],[3,6],[3,5],[3,7],[3,4],[3,6],[3,7],[3,6],[3,6],[3,5],[3,3],[3,3],[6,4],[6,4],[6,5],[6,5],[10,1],[10,1],[42,1],[42,1],[12,0],[12,1],[12,3],[12,4],[12,6],[43,1],[43,2],[43,1],[13,0],[13,1],[48,0],[48,1],[48,3],[48,2],[49,1],[49,2],[49,6],[49,1],[49,1],[49,2],[17,3],[19,3],[19,3],[19,5],[19,1],[19,3],[19,6],[19,3],[19,6],[19,2],[19,2],[19,3],[19,3],[19,3],[19,2],[19,2],[19,2],[19,5],[19,3],[19,3],[19,3],[19,3],[19,3],[19,3],[19,3],[19,3],[19,3],[19,3],[19,3],[19,3],[19,2],[19,6],[19,6],[19,4],[19,3],[19,3],[19,4],[19,6],[19,2],[19,5],[19,1],[19,1],[19,2],[19,3],[19,5],[19,5],[19,2],[19,4],[19,4],[19,2],[19,2],[19,4],[19,6],[19,5],[19,7],[19,4],[19,5],[19,4],[19,3],[19,2],[19,2],[19,5],[82,1],[82,3],[94,1],[94,1],[94,3],[94,3],[94,5],[94,5],[95,3],[95,6],[95,1],[95,3],[95,3],[95,2],[95,2],[95,2],[95,1],[40,0],[40,1],[40,3],[40,4],[40,4],[5,3],[97,1],[97,1],[97,3],[73,0],[73,2],[73,5],[75,4],[75,6],[75,6],[75,8],[75,2],[75,4],[75,4],[75,6],[75,4],[75,6],[75,6],[75,8],[75,6],[75,5],[75,8],[75,7],[75,8],[75,10],[75,10],[75,2],[75,4],[75,4],[75,6],[20,1],[20,2],[20,3],[20,3],[83,3],[83,4],[90,2],[90,0],[91,2],[91,0],[102,1]],
-performAction: function anonymous(yytext,yyleng,yylineno,yy,yystate,$$) {
+performAction: function anonymous(yytext,yyleng,yylineno,yy,yystate,$$
+/**/) {
 
 var $0 = $$.length - 1;
 switch (yystate) {
@@ -226,7 +227,7 @@ case 96:this.$ = yy.Block($$[$0-2]).pipe([$$[$0]], $$[$0-1]);
 break;
 case 97:this.$ = yy.Existence($$[$0-1].unwrap(), true);
 break;
-case 98:this.$ = yy.L(yylineno, yy.Fun($$[$0-4], $$[$0], /~/.test($$[$0-1]), /--|~~/.test($$[$0-1]), /!/.test($$[$0-1])));
+case 98:this.$ = yy.L(yylineno, yy.Fun($$[$0-4], $$[$0], /~/.test($$[$0-1]), /--|~~/.test($$[$0-1]), /!/.test($$[$0-1]), /\*/.test($$[$0-1])));
 break;
 case 99:this.$ = yy.L(yylineno, yy.Fun($$[$0-3], $$[$0]).named($$[$0-5]));
 break;
diff --git a/package.json b/package.json
index 4b76b8d43..707b5d141 100644
--- a/package.json
+++ b/package.json
@@ -40,6 +40,7 @@
   "scripts": {
     "pretest": "bin/slake build && bin/slake build:parser && bin/slake build",
     "test": "bin/slake test",
+    "test-harmony": "node --harmony ./bin/slake test",
     "posttest": "git checkout -- lib"
   },
   "preferGlobal": true,
diff --git a/package.json.ls b/package.json.ls
index 65be7af7d..0c1e302a5 100644
--- a/package.json.ls
+++ b/package.json.ls
@@ -36,6 +36,7 @@ bin  :
 scripts:
   pretest: "bin/slake build && bin/slake build:parser && bin/slake build"
   test: "bin/slake test"
+  \test-harmony : "node --harmony ./bin/slake test"
   posttest: "git checkout -- lib"
 
 preferGlobal: true
diff --git a/src/ast.ls b/src/ast.ls
index 2859968fb..4f383f0cc 100644
--- a/src/ast.ls
+++ b/src/ast.ls
@@ -1012,7 +1012,8 @@ class exports.Unary extends Node
               #{ it.compile o, LEVEL_LIST }).slice(8, -1)"
     code = it.compile o, LEVEL_OP + PREC.unary
     if @post then code += op else
-      op += ' ' if op in <[ new typeof delete ]>
+      op = 'yield* ' if op is \yieldfrom
+      op += ' ' if op in <[ new typeof delete yield ]>
                 or op in <[ + - ]> and op is code.charAt!
       code = op + code
     if o.level < LEVEL_CALL then code else "(#code)"
@@ -1591,7 +1592,7 @@ class exports.Existence extends Node implements Negatable
 #### Fun
 # A function definition. This is the only node that creates a `new Scope`.
 class exports.Fun extends Node
-  (@params or [], @body or Block!, @bound and \this$, @curried or false, @hushed = false) ~>
+  (@params or [], @body or Block!, @bound and \this$, @curried or false, @hushed = false, @generator = false) ~>
 
   children: <[ params body ]>
 
@@ -1623,6 +1624,10 @@ class exports.Fun extends Node
     o.indent += TAB
     {body, name, tab} = this
     code = \function
+    if @generator
+      @ctor and @carp "a constructor can't be a generator"
+      @hushed and @carp "a generator is hushed by default"
+      code += \*
     if @bound is \this$
       if @ctor
         scope.assign \this$ 'this instanceof ctor$ ? this : new ctor$'
@@ -1637,7 +1642,7 @@ class exports.Fun extends Node
       pscope.add name, \function, this
     if @statement or name and @labeled
       code += ' ' + scope.add name, \function, this
-    @hushed or @ctor or @newed or body.makeReturn!
+    @hushed or @ctor or @newed or @generator or body.makeReturn!
     code += "(#{ @compileParams o, scope }){"
     code += "\n#that\n#tab" if body.compileWithDeclarations o
     code += \}
diff --git a/src/grammar.ls b/src/grammar.ls
index 1926560fa..5b0fc49be 100644
--- a/src/grammar.ls
+++ b/src/grammar.ls
@@ -245,7 +245,7 @@ bnf =
 
     # The function literal can be either anonymous with `->`,
     o 'PARAM( ArgList OptComma )PARAM -> Block'
-    , -> L Fun $2, $6, /~/.test($5), /--|~~/.test($5), /!/.test($5)
+    , -> L Fun $2, $6, /~/.test($5), /--|~~/.test($5), /!/.test($5), /\*/.test($5)
     # or named with `function`.
     o 'FUNCTION CALL( ArgList OptComma )CALL Block' -> L Fun($3, $6)named $1
 
diff --git a/src/lexer.ls b/src/lexer.ls
index 181fb1158..683df1019 100644
--- a/src/lexer.ls
+++ b/src/lexer.ls
@@ -123,7 +123,7 @@ exports import
     switch id
     case <[ true false on off yes no null void arguments debugger ]>
       tag = \LITERAL
-    case \new \do \typeof \delete                      then tag = \UNARY
+    case <[ new do typeof delete yield ]>              then tag = \UNARY
     case \return \throw                                then tag = \HURL
     case \break  \continue                             then tag = \JUMP
     case \this \eval \super then return @token(\LITERAL id, true)length
@@ -211,7 +211,11 @@ exports import
         or last.1 is \import and \All
           last.1 += that
           return 3
-      case \from then @forange! and tag = \FROM
+      case \from
+        if last.1 is \yield
+          last.1 += \from
+          return 4
+        @forange! and tag = \FROM
       case \to \til
         @forange! and @tokens.push [\FROM '' @line] [\STRNUM \0 @line]
         if @fget \from
@@ -539,6 +543,9 @@ exports import
       @token \IMPORT \<<
       return sym.length
     case \*
+      if @last.0 is \->
+        @last.1 += \* if @last.0 is \->
+        return 1
       if @last.0 in <[ NEWLINE INDENT THEN => ]> and
          (INLINEDENT <<< lastIndex: index+1)exec code .0.length
         @tokens.push [\LITERAL \void @line] [\ASSIGN \= @line]
@@ -1215,13 +1222,13 @@ KEYWORDS_SHARED = <[
   true false null this void super return throw break continue
   if else for while switch case default try catch finally
   function class extends implements new do delete typeof in instanceof
-  let with var const import export debugger
+  let with var const import export debugger yield
 ]>
 
 # The list of keywords that are reserved by JavaScript, but not used.
 # We throw a syntax error for these to avoid runtime errors.
 KEYWORDS_UNUSED =
-  <[ enum interface package private protected public static yield ]>
+  <[ enum interface package private protected public static ]>
 
 JS_KEYWORDS = KEYWORDS_SHARED ++ KEYWORDS_UNUSED
 
diff --git a/test/compilation.ls b/test/compilation.ls
index 68cdb2bf4..74b942259 100644
--- a/test/compilation.ls
+++ b/test/compilation.ls
@@ -197,5 +197,12 @@ eq "var a, b, c;\na = require('a');\nb = require('b');\nc = require('c');" bare
 # JS literal
 eq 'some js code!' bare '``some js code!``'
 
+# generators
+compileThrows "a constructor can't be a generator" 1 'class => ->*'
+compileThrows "a generator is hushed by default" 1 '!->*'
+
+# https://github.com/jashkenas/coffee-script/pull/3240#issuecomment-38344281
+eq '(function*(){\n  var body;\n  body = (yield fn).body;\n});' bare '->* {body} = yield fn'
+
 # [livescript#279](https://github.com/gkz/LiveScript/issues/279)
-################################################################
+################################################################
\ No newline at end of file
diff --git a/test/generators.ls b/test/generators.ls
new file mode 100644
index 000000000..c09d2c33c
--- /dev/null
+++ b/test/generators.ls
@@ -0,0 +1,68 @@
+# Generators
+# -----------------
+#
+# * Generator Definition
+
+# generator as argument
+ok ->* 1
+
+# named generator function
+ok <| :fn ->* 2
+
+# generator definition
+x = ->*
+  yield 0
+  yield 1
+  yield 2
+
+y = x!
+z = y.next!
+eq z.value, 0
+eq z.done, false
+z = y.next!
+eq z.value, 1
+eq z.done, false
+z = y.next!
+eq z.value, 2
+eq z.done, false
+z = y.next!
+eq z.value, void
+eq z.done, true
+
+# yield from
+first = ->*
+  i = 0
+  loop => yield i++
+second = ->*
+  yield from first!
+list = second!
+for i to 3 
+  {value} = list.next!
+  eq value, i
+
+# curried bound generators
+class A
+  val: 5
+  curried: (x, y) ~~>*
+    yield @val + x + y
+fn = (new A).curried
+yield-add = fn 2
+y = yield-add 3
+z = y.next!
+eq z.value, 10
+eq z.done, false
+z = y.next!
+eq z.value, void
+eq z.done, true
+
+# bound generator
+obj =
+  bound: ->
+    do ~>*
+      return this
+  unbound: ->
+    do ->*
+      return this
+
+eq obj, obj.bound().next().value
+ok obj isnt obj.unbound().next().value
\ No newline at end of file