diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 37905e1047c..a8ba45b8825 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -13472,10 +13472,14 @@ namespace ts {
         }
 
         function isInParameterInitializerBeforeContainingFunction(node: Node) {
+            let inBindingInitializer = false;
             while (node.parent && !isFunctionLike(node.parent)) {
-                if (node.parent.kind === SyntaxKind.Parameter && (<ParameterDeclaration>node.parent).initializer === node) {
+                if (isParameter(node.parent) && (inBindingInitializer || node.parent.initializer === node)) {
                     return true;
                 }
+                if (isBindingElement(node.parent) && node.parent.initializer === node) {
+                    inBindingInitializer = true;
+                }
 
                 node = node.parent;
             }
diff --git a/src/compiler/factory.ts b/src/compiler/factory.ts
index e8dfcbc1e94..35d35b40826 100644
--- a/src/compiler/factory.ts
+++ b/src/compiler/factory.ts
@@ -3709,7 +3709,7 @@ namespace ts {
         while (statementOffset < numStatements) {
             const statement = source[statementOffset];
             if (getEmitFlags(statement) & EmitFlags.CustomPrologue) {
-                target.push(visitor ? visitNode(statement, visitor, isStatement) : statement);
+                append(target, visitor ? visitNode(statement, visitor, isStatement) : statement);
             }
             else {
                 break;
diff --git a/tests/baselines/reference/expressionsForbiddenInParameterInitializers.errors.txt b/tests/baselines/reference/expressionsForbiddenInParameterInitializers.errors.txt
new file mode 100644
index 00000000000..605b6d78ea3
--- /dev/null
+++ b/tests/baselines/reference/expressionsForbiddenInParameterInitializers.errors.txt
@@ -0,0 +1,15 @@
+tests/cases/compiler/bar.ts(1,35): error TS2524: 'await' expressions cannot be used in a parameter initializer.
+tests/cases/compiler/bar.ts(4,31): error TS2523: 'yield' expressions cannot be used in a parameter initializer.
+
+
+==== tests/cases/compiler/bar.ts (2 errors) ====
+    export async function foo({ foo = await import("./bar") }) {
+                                      ~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2524: 'await' expressions cannot be used in a parameter initializer.
+    }
+    
+    export function* foo2({ foo = yield "a" }) {
+                                  ~~~~~~~~~
+!!! error TS2523: 'yield' expressions cannot be used in a parameter initializer.
+    }
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/expressionsForbiddenInParameterInitializers.js b/tests/baselines/reference/expressionsForbiddenInParameterInitializers.js
new file mode 100644
index 00000000000..d66b3c8e06d
--- /dev/null
+++ b/tests/baselines/reference/expressionsForbiddenInParameterInitializers.js
@@ -0,0 +1,76 @@
+//// [bar.ts]
+export async function foo({ foo = await import("./bar") }) {
+}
+
+export function* foo2({ foo = yield "a" }) {
+}
+
+
+//// [bar.js]
+"use strict";
+var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, generator) {
+    return new (P || (P = Promise))(function (resolve, reject) {
+        function fulfilled(value) { try { step(generator.next(value)); } catch (e) { reject(e); } }
+        function rejected(value) { try { step(generator["throw"](value)); } catch (e) { reject(e); } }
+        function step(result) { result.done ? resolve(result.value) : new P(function (resolve) { resolve(result.value); }).then(fulfilled, rejected); }
+        step((generator = generator.apply(thisArg, _arguments || [])).next());
+    });
+};
+var __generator = (this && this.__generator) || function (thisArg, body) {
+    var _ = { label: 0, sent: function() { if (t[0] & 1) throw t[1]; return t[1]; }, trys: [], ops: [] }, f, y, t, g;
+    return g = { next: verb(0), "throw": verb(1), "return": verb(2) }, typeof Symbol === "function" && (g[Symbol.iterator] = function() { return this; }), g;
+    function verb(n) { return function (v) { return step([n, v]); }; }
+    function step(op) {
+        if (f) throw new TypeError("Generator is already executing.");
+        while (_) try {
+            if (f = 1, y && (t = y[op[0] & 2 ? "return" : op[0] ? "throw" : "next"]) && !(t = t.call(y, op[1])).done) return t;
+            if (y = 0, t) op = [0, t.value];
+            switch (op[0]) {
+                case 0: case 1: t = op; break;
+                case 4: _.label++; return { value: op[1], done: false };
+                case 5: _.label++; y = op[1]; op = [0]; continue;
+                case 7: op = _.ops.pop(); _.trys.pop(); continue;
+                default:
+                    if (!(t = _.trys, t = t.length > 0 && t[t.length - 1]) && (op[0] === 6 || op[0] === 2)) { _ = 0; continue; }
+                    if (op[0] === 3 && (!t || (op[1] > t[0] && op[1] < t[3]))) { _.label = op[1]; break; }
+                    if (op[0] === 6 && _.label < t[1]) { _.label = t[1]; t = op; break; }
+                    if (t && _.label < t[2]) { _.label = t[2]; _.ops.push(op); break; }
+                    if (t[2]) _.ops.pop();
+                    _.trys.pop(); continue;
+            }
+            op = body.call(thisArg, _);
+        } catch (e) { op = [6, e]; y = 0; } finally { f = t = 0; }
+        if (op[0] & 5) throw op[1]; return { value: op[0] ? op[1] : void 0, done: true };
+    }
+};
+exports.__esModule = true;
+function foo(_a) {
+    var _b = _a.foo, foo = _b === void 0 ? yield Promise.resolve().then(function () { return require("./bar"); }) : _b;
+    return __awaiter(this, void 0, void 0, function () {
+        return __generator(this, function (_c) {
+            return [2 /*return*/];
+        });
+    });
+}
+exports.foo = foo;
+function foo2(_a) {
+    var _b, foo, _c;
+    return __generator(this, function (_d) {
+        switch (_d.label) {
+            case 0:
+                _b = _a.foo;
+                if (!(_b === void 0)) return [3 /*break*/, 2];
+                return [4 /*yield*/, "a"];
+            case 1:
+                _c = _d.sent();
+                return [3 /*break*/, 3];
+            case 2:
+                _c = _b;
+                _d.label = 3;
+            case 3:
+                foo = _c;
+                return [2 /*return*/];
+        }
+    });
+}
+exports.foo2 = foo2;
diff --git a/tests/baselines/reference/expressionsForbiddenInParameterInitializers.symbols b/tests/baselines/reference/expressionsForbiddenInParameterInitializers.symbols
new file mode 100644
index 00000000000..6ad101f3c17
--- /dev/null
+++ b/tests/baselines/reference/expressionsForbiddenInParameterInitializers.symbols
@@ -0,0 +1,12 @@
+=== tests/cases/compiler/bar.ts ===
+export async function foo({ foo = await import("./bar") }) {
+>foo : Symbol(foo, Decl(bar.ts, 0, 0))
+>foo : Symbol(foo, Decl(bar.ts, 0, 27))
+>"./bar" : Symbol("tests/cases/compiler/bar", Decl(bar.ts, 0, 0))
+}
+
+export function* foo2({ foo = yield "a" }) {
+>foo2 : Symbol(foo2, Decl(bar.ts, 1, 1))
+>foo : Symbol(foo, Decl(bar.ts, 3, 23))
+}
+
diff --git a/tests/baselines/reference/expressionsForbiddenInParameterInitializers.types b/tests/baselines/reference/expressionsForbiddenInParameterInitializers.types
new file mode 100644
index 00000000000..1fd11b0513b
--- /dev/null
+++ b/tests/baselines/reference/expressionsForbiddenInParameterInitializers.types
@@ -0,0 +1,16 @@
+=== tests/cases/compiler/bar.ts ===
+export async function foo({ foo = await import("./bar") }) {
+>foo : ({ foo }: { foo?: typeof "tests/cases/compiler/bar"; }) => Promise<void>
+>foo : typeof "tests/cases/compiler/bar"
+>await import("./bar") : typeof "tests/cases/compiler/bar"
+>import("./bar") : Promise<typeof "tests/cases/compiler/bar">
+>"./bar" : "./bar"
+}
+
+export function* foo2({ foo = yield "a" }) {
+>foo2 : ({ foo }: { foo?: any; }) => IterableIterator<any>
+>foo : any
+>yield "a" : any
+>"a" : "a"
+}
+
diff --git a/tests/cases/compiler/expressionsForbiddenInParameterInitializers.ts b/tests/cases/compiler/expressionsForbiddenInParameterInitializers.ts
new file mode 100644
index 00000000000..ea4dce15408
--- /dev/null
+++ b/tests/cases/compiler/expressionsForbiddenInParameterInitializers.ts
@@ -0,0 +1,7 @@
+// @lib: es6
+// @filename: bar.ts
+export async function foo({ foo = await import("./bar") }) {
+}
+
+export function* foo2({ foo = yield "a" }) {
+}