diff --git a/src/compiler/emitter.ts b/src/compiler/emitter.ts
index 88847999a4b..09ae33c4edc 100644
--- a/src/compiler/emitter.ts
+++ b/src/compiler/emitter.ts
@@ -4514,32 +4514,34 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, Promi
 
                 convertedLoopState = undefined;
                 tempFlags = 0;
-                tempVariables = undefined;
-                tempParameters = undefined;
-
-                // When targeting ES6, emit arrow function natively in ES6
-                if (shouldEmitAsArrowFunction(node)) {
-                    emitSignatureParametersForArrow(node);
-                    write(" =>");
-                }
-                else {
-                    emitSignatureParameters(node);
-                }
-
-                const isAsync = isAsyncFunctionLike(node);
-                if (isAsync && languageVersion === ScriptTarget.ES6) {
-                    emitAsyncFunctionBodyForES6(node);
-                }
-                else {
-                    emitFunctionBody(node);
-                }
-
-                if (!isES6ExportedDeclaration(node)) {
-                    emitExportMemberAssignment(node);
-                }
-
-                Debug.assert(convertedLoopState === undefined);
-                convertedLoopState = saveConvertedLoopState;
+                tempVariables = undefined;
+                tempParameters = undefined;
+
+                // When targeting ES6, emit arrow function natively in ES6
+                if (shouldEmitAsArrowFunction(node)) {
+                    emitSignatureParametersForArrow(node);
+                    write(" =>");
+                }
+                else {
+                    emitSignatureParameters(node);
+                }
+
+                // Even though generators are a ES6 only feature, the functionality is wiedely supported
+                // in current browsers and latest node, therefore showing some tolerance
+                const isAsync = isAsyncFunctionLike(node);
+                if (isAsync && (languageVersion === ScriptTarget.ES6 || languageVersion === ScriptTarget.ES2015 || languageVersion === ScriptTarget.ES5)) {
+                    emitAsyncFunctionBodyForES6(node);
+                }
+                else {
+                    emitFunctionBody(node);
+                }
+
+                if (!isES6ExportedDeclaration(node)) {
+                    emitExportMemberAssignment(node);
+                }
+
+                Debug.assert(convertedLoopState === undefined);
+                convertedLoopState = saveConvertedLoopState;
 
                 tempFlags = saveTempFlags;
                 tempVariables = saveTempVariables;