diff --git a/src/compiler/transformers/esnext.ts b/src/compiler/transformers/esnext.ts
index 9e68e48886f..3aa5be551a6 100644
--- a/src/compiler/transformers/esnext.ts
+++ b/src/compiler/transformers/esnext.ts
@@ -924,7 +924,7 @@ namespace ts {
             var __asyncDelegator = (this && this.__asyncDelegator) || function (o) {
                 var i = { next: verb("next"), "throw": verb("throw", function (e) { throw e; }), "return": verb("return", function (v) { return { value: v, done: true }; }) }, p;
                 return o = __asyncValues(o), i[Symbol.iterator] = function () { return this; }, i;
-                function verb(n, f) { return function (v) { return v = p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
+                function verb(n, f) { return function (v) { return v = p && n === "throw" ? f(v) : p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
             };
         `
     };
diff --git a/tests/baselines/reference/emitter.asyncGenerators.classMethods.es2015.js b/tests/baselines/reference/emitter.asyncGenerators.classMethods.es2015.js
index e5a8800beef..fbefef62d05 100644
--- a/tests/baselines/reference/emitter.asyncGenerators.classMethods.es2015.js
+++ b/tests/baselines/reference/emitter.asyncGenerators.classMethods.es2015.js
@@ -126,7 +126,7 @@ class C3 {
 var __asyncDelegator = (this && this.__asyncDelegator) || function (o) {
     var i = { next: verb("next"), "throw": verb("throw", function (e) { throw e; }), "return": verb("return", function (v) { return { value: v, done: true }; }) }, p;
     return o = __asyncValues(o), i[Symbol.iterator] = function () { return this; }, i;
-    function verb(n, f) { return function (v) { return v = p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
+    function verb(n, f) { return function (v) { return v = p && n === "throw" ? f(v) : p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
 };
 var __asyncValues = (this && this.__asyncIterator) || function (o) {
     if (!Symbol.asyncIterator) throw new TypeError("Symbol.asyncIterator is not defined.");
@@ -170,7 +170,7 @@ var __asyncGenerator = (this && this.__asyncGenerator) || function (thisArg, _ar
 var __asyncDelegator = (this && this.__asyncDelegator) || function (o) {
     var i = { next: verb("next"), "throw": verb("throw", function (e) { throw e; }), "return": verb("return", function (v) { return { value: v, done: true }; }) }, p;
     return o = __asyncValues(o), i[Symbol.iterator] = function () { return this; }, i;
-    function verb(n, f) { return function (v) { return v = p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
+    function verb(n, f) { return function (v) { return v = p && n === "throw" ? f(v) : p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
 };
 var __asyncValues = (this && this.__asyncIterator) || function (o) {
     if (!Symbol.asyncIterator) throw new TypeError("Symbol.asyncIterator is not defined.");
diff --git a/tests/baselines/reference/emitter.asyncGenerators.classMethods.es5.js b/tests/baselines/reference/emitter.asyncGenerators.classMethods.es5.js
index 67de0cff5df..0c58c4735a0 100644
--- a/tests/baselines/reference/emitter.asyncGenerators.classMethods.es5.js
+++ b/tests/baselines/reference/emitter.asyncGenerators.classMethods.es5.js
@@ -262,7 +262,7 @@ var __generator = (this && this.__generator) || function (thisArg, body) {
 var __asyncDelegator = (this && this.__asyncDelegator) || function (o) {
     var i = { next: verb("next"), "throw": verb("throw", function (e) { throw e; }), "return": verb("return", function (v) { return { value: v, done: true }; }) }, p;
     return o = __asyncValues(o), i[Symbol.iterator] = function () { return this; }, i;
-    function verb(n, f) { return function (v) { return v = p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
+    function verb(n, f) { return function (v) { return v = p && n === "throw" ? f(v) : p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
 };
 var __asyncValues = (this && this.__asyncIterator) || function (o) {
     if (!Symbol.asyncIterator) throw new TypeError("Symbol.asyncIterator is not defined.");
@@ -354,7 +354,7 @@ var __asyncGenerator = (this && this.__asyncGenerator) || function (thisArg, _ar
 var __asyncDelegator = (this && this.__asyncDelegator) || function (o) {
     var i = { next: verb("next"), "throw": verb("throw", function (e) { throw e; }), "return": verb("return", function (v) { return { value: v, done: true }; }) }, p;
     return o = __asyncValues(o), i[Symbol.iterator] = function () { return this; }, i;
-    function verb(n, f) { return function (v) { return v = p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
+    function verb(n, f) { return function (v) { return v = p && n === "throw" ? f(v) : p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
 };
 var __asyncValues = (this && this.__asyncIterator) || function (o) {
     if (!Symbol.asyncIterator) throw new TypeError("Symbol.asyncIterator is not defined.");
diff --git a/tests/baselines/reference/emitter.asyncGenerators.functionDeclarations.es2015.js b/tests/baselines/reference/emitter.asyncGenerators.functionDeclarations.es2015.js
index 36e701072da..daf188ba33f 100644
--- a/tests/baselines/reference/emitter.asyncGenerators.functionDeclarations.es2015.js
+++ b/tests/baselines/reference/emitter.asyncGenerators.functionDeclarations.es2015.js
@@ -89,7 +89,7 @@ function f3() {
 var __asyncDelegator = (this && this.__asyncDelegator) || function (o) {
     var i = { next: verb("next"), "throw": verb("throw", function (e) { throw e; }), "return": verb("return", function (v) { return { value: v, done: true }; }) }, p;
     return o = __asyncValues(o), i[Symbol.iterator] = function () { return this; }, i;
-    function verb(n, f) { return function (v) { return v = p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
+    function verb(n, f) { return function (v) { return v = p && n === "throw" ? f(v) : p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
 };
 var __asyncValues = (this && this.__asyncIterator) || function (o) {
     if (!Symbol.asyncIterator) throw new TypeError("Symbol.asyncIterator is not defined.");
@@ -131,7 +131,7 @@ var __asyncGenerator = (this && this.__asyncGenerator) || function (thisArg, _ar
 var __asyncDelegator = (this && this.__asyncDelegator) || function (o) {
     var i = { next: verb("next"), "throw": verb("throw", function (e) { throw e; }), "return": verb("return", function (v) { return { value: v, done: true }; }) }, p;
     return o = __asyncValues(o), i[Symbol.iterator] = function () { return this; }, i;
-    function verb(n, f) { return function (v) { return v = p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
+    function verb(n, f) { return function (v) { return v = p && n === "throw" ? f(v) : p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
 };
 var __asyncValues = (this && this.__asyncIterator) || function (o) {
     if (!Symbol.asyncIterator) throw new TypeError("Symbol.asyncIterator is not defined.");
diff --git a/tests/baselines/reference/emitter.asyncGenerators.functionDeclarations.es5.js b/tests/baselines/reference/emitter.asyncGenerators.functionDeclarations.es5.js
index 4743e40b47b..71f685e24dd 100644
--- a/tests/baselines/reference/emitter.asyncGenerators.functionDeclarations.es5.js
+++ b/tests/baselines/reference/emitter.asyncGenerators.functionDeclarations.es5.js
@@ -216,7 +216,7 @@ var __generator = (this && this.__generator) || function (thisArg, body) {
 var __asyncDelegator = (this && this.__asyncDelegator) || function (o) {
     var i = { next: verb("next"), "throw": verb("throw", function (e) { throw e; }), "return": verb("return", function (v) { return { value: v, done: true }; }) }, p;
     return o = __asyncValues(o), i[Symbol.iterator] = function () { return this; }, i;
-    function verb(n, f) { return function (v) { return v = p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
+    function verb(n, f) { return function (v) { return v = p && n === "throw" ? f(v) : p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
 };
 var __asyncValues = (this && this.__asyncIterator) || function (o) {
     if (!Symbol.asyncIterator) throw new TypeError("Symbol.asyncIterator is not defined.");
@@ -303,7 +303,7 @@ var __asyncGenerator = (this && this.__asyncGenerator) || function (thisArg, _ar
 var __asyncDelegator = (this && this.__asyncDelegator) || function (o) {
     var i = { next: verb("next"), "throw": verb("throw", function (e) { throw e; }), "return": verb("return", function (v) { return { value: v, done: true }; }) }, p;
     return o = __asyncValues(o), i[Symbol.iterator] = function () { return this; }, i;
-    function verb(n, f) { return function (v) { return v = p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
+    function verb(n, f) { return function (v) { return v = p && n === "throw" ? f(v) : p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
 };
 var __asyncValues = (this && this.__asyncIterator) || function (o) {
     if (!Symbol.asyncIterator) throw new TypeError("Symbol.asyncIterator is not defined.");
diff --git a/tests/baselines/reference/emitter.asyncGenerators.functionExpressions.es2015.js b/tests/baselines/reference/emitter.asyncGenerators.functionExpressions.es2015.js
index b6bca871866..bb2562db780 100644
--- a/tests/baselines/reference/emitter.asyncGenerators.functionExpressions.es2015.js
+++ b/tests/baselines/reference/emitter.asyncGenerators.functionExpressions.es2015.js
@@ -89,7 +89,7 @@ const f3 = function () {
 var __asyncDelegator = (this && this.__asyncDelegator) || function (o) {
     var i = { next: verb("next"), "throw": verb("throw", function (e) { throw e; }), "return": verb("return", function (v) { return { value: v, done: true }; }) }, p;
     return o = __asyncValues(o), i[Symbol.iterator] = function () { return this; }, i;
-    function verb(n, f) { return function (v) { return v = p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
+    function verb(n, f) { return function (v) { return v = p && n === "throw" ? f(v) : p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
 };
 var __asyncValues = (this && this.__asyncIterator) || function (o) {
     if (!Symbol.asyncIterator) throw new TypeError("Symbol.asyncIterator is not defined.");
@@ -131,7 +131,7 @@ var __asyncGenerator = (this && this.__asyncGenerator) || function (thisArg, _ar
 var __asyncDelegator = (this && this.__asyncDelegator) || function (o) {
     var i = { next: verb("next"), "throw": verb("throw", function (e) { throw e; }), "return": verb("return", function (v) { return { value: v, done: true }; }) }, p;
     return o = __asyncValues(o), i[Symbol.iterator] = function () { return this; }, i;
-    function verb(n, f) { return function (v) { return v = p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
+    function verb(n, f) { return function (v) { return v = p && n === "throw" ? f(v) : p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
 };
 var __asyncValues = (this && this.__asyncIterator) || function (o) {
     if (!Symbol.asyncIterator) throw new TypeError("Symbol.asyncIterator is not defined.");
diff --git a/tests/baselines/reference/emitter.asyncGenerators.functionExpressions.es5.js b/tests/baselines/reference/emitter.asyncGenerators.functionExpressions.es5.js
index ec19e91e446..1863548c141 100644
--- a/tests/baselines/reference/emitter.asyncGenerators.functionExpressions.es5.js
+++ b/tests/baselines/reference/emitter.asyncGenerators.functionExpressions.es5.js
@@ -216,7 +216,7 @@ var __generator = (this && this.__generator) || function (thisArg, body) {
 var __asyncDelegator = (this && this.__asyncDelegator) || function (o) {
     var i = { next: verb("next"), "throw": verb("throw", function (e) { throw e; }), "return": verb("return", function (v) { return { value: v, done: true }; }) }, p;
     return o = __asyncValues(o), i[Symbol.iterator] = function () { return this; }, i;
-    function verb(n, f) { return function (v) { return v = p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
+    function verb(n, f) { return function (v) { return v = p && n === "throw" ? f(v) : p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
 };
 var __asyncValues = (this && this.__asyncIterator) || function (o) {
     if (!Symbol.asyncIterator) throw new TypeError("Symbol.asyncIterator is not defined.");
@@ -303,7 +303,7 @@ var __asyncGenerator = (this && this.__asyncGenerator) || function (thisArg, _ar
 var __asyncDelegator = (this && this.__asyncDelegator) || function (o) {
     var i = { next: verb("next"), "throw": verb("throw", function (e) { throw e; }), "return": verb("return", function (v) { return { value: v, done: true }; }) }, p;
     return o = __asyncValues(o), i[Symbol.iterator] = function () { return this; }, i;
-    function verb(n, f) { return function (v) { return v = p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
+    function verb(n, f) { return function (v) { return v = p && n === "throw" ? f(v) : p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
 };
 var __asyncValues = (this && this.__asyncIterator) || function (o) {
     if (!Symbol.asyncIterator) throw new TypeError("Symbol.asyncIterator is not defined.");
diff --git a/tests/baselines/reference/emitter.asyncGenerators.objectLiteralMethods.es2015.js b/tests/baselines/reference/emitter.asyncGenerators.objectLiteralMethods.es2015.js
index f37428f20cb..5a200349c02 100644
--- a/tests/baselines/reference/emitter.asyncGenerators.objectLiteralMethods.es2015.js
+++ b/tests/baselines/reference/emitter.asyncGenerators.objectLiteralMethods.es2015.js
@@ -109,7 +109,7 @@ const o3 = {
 var __asyncDelegator = (this && this.__asyncDelegator) || function (o) {
     var i = { next: verb("next"), "throw": verb("throw", function (e) { throw e; }), "return": verb("return", function (v) { return { value: v, done: true }; }) }, p;
     return o = __asyncValues(o), i[Symbol.iterator] = function () { return this; }, i;
-    function verb(n, f) { return function (v) { return v = p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
+    function verb(n, f) { return function (v) { return v = p && n === "throw" ? f(v) : p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
 };
 var __asyncValues = (this && this.__asyncIterator) || function (o) {
     if (!Symbol.asyncIterator) throw new TypeError("Symbol.asyncIterator is not defined.");
@@ -153,7 +153,7 @@ var __asyncGenerator = (this && this.__asyncGenerator) || function (thisArg, _ar
 var __asyncDelegator = (this && this.__asyncDelegator) || function (o) {
     var i = { next: verb("next"), "throw": verb("throw", function (e) { throw e; }), "return": verb("return", function (v) { return { value: v, done: true }; }) }, p;
     return o = __asyncValues(o), i[Symbol.iterator] = function () { return this; }, i;
-    function verb(n, f) { return function (v) { return v = p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
+    function verb(n, f) { return function (v) { return v = p && n === "throw" ? f(v) : p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
 };
 var __asyncValues = (this && this.__asyncIterator) || function (o) {
     if (!Symbol.asyncIterator) throw new TypeError("Symbol.asyncIterator is not defined.");
diff --git a/tests/baselines/reference/emitter.asyncGenerators.objectLiteralMethods.es5.js b/tests/baselines/reference/emitter.asyncGenerators.objectLiteralMethods.es5.js
index d3facb5b7cf..abb3f0ca074 100644
--- a/tests/baselines/reference/emitter.asyncGenerators.objectLiteralMethods.es5.js
+++ b/tests/baselines/reference/emitter.asyncGenerators.objectLiteralMethods.es5.js
@@ -236,7 +236,7 @@ var __generator = (this && this.__generator) || function (thisArg, body) {
 var __asyncDelegator = (this && this.__asyncDelegator) || function (o) {
     var i = { next: verb("next"), "throw": verb("throw", function (e) { throw e; }), "return": verb("return", function (v) { return { value: v, done: true }; }) }, p;
     return o = __asyncValues(o), i[Symbol.iterator] = function () { return this; }, i;
-    function verb(n, f) { return function (v) { return v = p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
+    function verb(n, f) { return function (v) { return v = p && n === "throw" ? f(v) : p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
 };
 var __asyncValues = (this && this.__asyncIterator) || function (o) {
     if (!Symbol.asyncIterator) throw new TypeError("Symbol.asyncIterator is not defined.");
@@ -325,7 +325,7 @@ var __asyncGenerator = (this && this.__asyncGenerator) || function (thisArg, _ar
 var __asyncDelegator = (this && this.__asyncDelegator) || function (o) {
     var i = { next: verb("next"), "throw": verb("throw", function (e) { throw e; }), "return": verb("return", function (v) { return { value: v, done: true }; }) }, p;
     return o = __asyncValues(o), i[Symbol.iterator] = function () { return this; }, i;
-    function verb(n, f) { return function (v) { return v = p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
+    function verb(n, f) { return function (v) { return v = p && n === "throw" ? f(v) : p && v.done ? v : { value: p ? ["yield", v.value] : ["await", (o[n] || f).call(o, v)], done: false }, p = !p, v; }; }
 };
 var __asyncValues = (this && this.__asyncIterator) || function (o) {
     if (!Symbol.asyncIterator) throw new TypeError("Symbol.asyncIterator is not defined.");