diff --git a/src/compiler/emitter.ts b/src/compiler/emitter.ts
index 357a15507a457..d0f7918dc8900 100644
--- a/src/compiler/emitter.ts
+++ b/src/compiler/emitter.ts
@@ -1817,6 +1817,10 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, ge
                 else if (node.parent.kind === SyntaxKind.ConditionalExpression && (<ConditionalExpression>node.parent).condition === node) {
                     return true;
                 }
+                else if (node.parent.kind === SyntaxKind.PrefixUnaryExpression || node.parent.kind === SyntaxKind.DeleteExpression ||
+                    node.parent.kind === SyntaxKind.TypeOfExpression || node.parent.kind === SyntaxKind.VoidExpression) {
+                    return true;
+                }
 
                 return false;
             }
diff --git a/src/compiler/parser.ts b/src/compiler/parser.ts
index f373d33955347..b5ba89887a26c 100644
--- a/src/compiler/parser.ts
+++ b/src/compiler/parser.ts
@@ -3381,10 +3381,6 @@ namespace ts {
          *
          */
         function parseUnaryExpressionOrHigher(): UnaryExpression | BinaryExpression {
-            if (isAwaitExpression()) {
-                return parseAwaitExpression();
-            }
-
             /**
              * ES7 UpdateExpression:
              *      1) LeftHandSideExpression[?Yield]
@@ -3452,13 +3448,15 @@ namespace ts {
                     return parseTypeOfExpression();
                 case SyntaxKind.VoidKeyword:
                     return parseVoidExpression();
-                case SyntaxKind.AwaitKeyword:
-                    return parseAwaitExpression();
                 case SyntaxKind.LessThanToken:
                     // This is modified UnaryExpression grammar in TypeScript
                     //  UnaryExpression (modified):
                     //      < type > UnaryExpression
                     return parseTypeAssertion();
+                case SyntaxKind.AwaitKeyword:
+                    if (isAwaitExpression()) {
+                        return parseAwaitExpression();
+                    }
                 default:
                     return parseIncrementExpression();
             }
@@ -3485,6 +3483,7 @@ namespace ts {
                 case SyntaxKind.DeleteKeyword:
                 case SyntaxKind.TypeOfKeyword:
                 case SyntaxKind.VoidKeyword:
+                case SyntaxKind.AwaitKeyword:
                     return false;
                 case SyntaxKind.LessThanToken:
                     // If we are not in JSX context, we are parsing TypeAssertion which is an UnaryExpression
diff --git a/tests/baselines/reference/await_unaryExpression_es6.js b/tests/baselines/reference/await_unaryExpression_es6.js
new file mode 100644
index 0000000000000..46065bdada925
--- /dev/null
+++ b/tests/baselines/reference/await_unaryExpression_es6.js
@@ -0,0 +1,47 @@
+//// [await_unaryExpression_es6.ts]
+
+async function bar() {
+    !await 42; // OK
+}
+
+async function bar1() {
+    +await 42; // OK
+}
+
+async function bar3() {
+    -await 42; // OK
+}
+
+async function bar4() {
+    ~await 42; // OK
+}
+
+//// [await_unaryExpression_es6.js]
+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());
+    });
+};
+function bar() {
+    return __awaiter(this, void 0, void 0, function* () {
+        !(yield 42); // OK
+    });
+}
+function bar1() {
+    return __awaiter(this, void 0, void 0, function* () {
+        +(yield 42); // OK
+    });
+}
+function bar3() {
+    return __awaiter(this, void 0, void 0, function* () {
+        -(yield 42); // OK
+    });
+}
+function bar4() {
+    return __awaiter(this, void 0, void 0, function* () {
+        ~(yield 42); // OK
+    });
+}
diff --git a/tests/baselines/reference/await_unaryExpression_es6.symbols b/tests/baselines/reference/await_unaryExpression_es6.symbols
new file mode 100644
index 0000000000000..81edd4b981b1b
--- /dev/null
+++ b/tests/baselines/reference/await_unaryExpression_es6.symbols
@@ -0,0 +1,25 @@
+=== tests/cases/conformance/async/es6/await_unaryExpression_es6.ts ===
+
+async function bar() {
+>bar : Symbol(bar, Decl(await_unaryExpression_es6.ts, 0, 0))
+
+    !await 42; // OK
+}
+
+async function bar1() {
+>bar1 : Symbol(bar1, Decl(await_unaryExpression_es6.ts, 3, 1))
+
+    +await 42; // OK
+}
+
+async function bar3() {
+>bar3 : Symbol(bar3, Decl(await_unaryExpression_es6.ts, 7, 1))
+
+    -await 42; // OK
+}
+
+async function bar4() {
+>bar4 : Symbol(bar4, Decl(await_unaryExpression_es6.ts, 11, 1))
+
+    ~await 42; // OK
+}
diff --git a/tests/baselines/reference/await_unaryExpression_es6.types b/tests/baselines/reference/await_unaryExpression_es6.types
new file mode 100644
index 0000000000000..2a4b7354d3ebf
--- /dev/null
+++ b/tests/baselines/reference/await_unaryExpression_es6.types
@@ -0,0 +1,37 @@
+=== tests/cases/conformance/async/es6/await_unaryExpression_es6.ts ===
+
+async function bar() {
+>bar : () => Promise<void>
+
+    !await 42; // OK
+>!await 42 : boolean
+>await 42 : number
+>42 : number
+}
+
+async function bar1() {
+>bar1 : () => Promise<void>
+
+    +await 42; // OK
+>+await 42 : number
+>await 42 : number
+>42 : number
+}
+
+async function bar3() {
+>bar3 : () => Promise<void>
+
+    -await 42; // OK
+>-await 42 : number
+>await 42 : number
+>42 : number
+}
+
+async function bar4() {
+>bar4 : () => Promise<void>
+
+    ~await 42; // OK
+>~await 42 : number
+>await 42 : number
+>42 : number
+}
diff --git a/tests/baselines/reference/await_unaryExpression_es6_1.js b/tests/baselines/reference/await_unaryExpression_es6_1.js
new file mode 100644
index 0000000000000..c6f5f1142c085
--- /dev/null
+++ b/tests/baselines/reference/await_unaryExpression_es6_1.js
@@ -0,0 +1,56 @@
+//// [await_unaryExpression_es6_1.ts]
+
+async function bar() {
+    !await 42; // OK
+}
+
+async function bar1() {
+    delete await 42; // OK
+}
+
+async function bar2() {
+    delete await 42; // OK
+}
+
+async function bar3() {
+    void await 42;
+}
+
+async function bar4() {
+    +await 42;
+}
+
+//// [await_unaryExpression_es6_1.js]
+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());
+    });
+};
+function bar() {
+    return __awaiter(this, void 0, void 0, function* () {
+        !(yield 42); // OK
+    });
+}
+function bar1() {
+    return __awaiter(this, void 0, void 0, function* () {
+        delete (yield 42); // OK
+    });
+}
+function bar2() {
+    return __awaiter(this, void 0, void 0, function* () {
+        delete (yield 42); // OK
+    });
+}
+function bar3() {
+    return __awaiter(this, void 0, void 0, function* () {
+        void (yield 42);
+    });
+}
+function bar4() {
+    return __awaiter(this, void 0, void 0, function* () {
+        +(yield 42);
+    });
+}
diff --git a/tests/baselines/reference/await_unaryExpression_es6_1.symbols b/tests/baselines/reference/await_unaryExpression_es6_1.symbols
new file mode 100644
index 0000000000000..ed7d7e4ed02e9
--- /dev/null
+++ b/tests/baselines/reference/await_unaryExpression_es6_1.symbols
@@ -0,0 +1,31 @@
+=== tests/cases/conformance/async/es6/await_unaryExpression_es6_1.ts ===
+
+async function bar() {
+>bar : Symbol(bar, Decl(await_unaryExpression_es6_1.ts, 0, 0))
+
+    !await 42; // OK
+}
+
+async function bar1() {
+>bar1 : Symbol(bar1, Decl(await_unaryExpression_es6_1.ts, 3, 1))
+
+    delete await 42; // OK
+}
+
+async function bar2() {
+>bar2 : Symbol(bar2, Decl(await_unaryExpression_es6_1.ts, 7, 1))
+
+    delete await 42; // OK
+}
+
+async function bar3() {
+>bar3 : Symbol(bar3, Decl(await_unaryExpression_es6_1.ts, 11, 1))
+
+    void await 42;
+}
+
+async function bar4() {
+>bar4 : Symbol(bar4, Decl(await_unaryExpression_es6_1.ts, 15, 1))
+
+    +await 42;
+}
diff --git a/tests/baselines/reference/await_unaryExpression_es6_1.types b/tests/baselines/reference/await_unaryExpression_es6_1.types
new file mode 100644
index 0000000000000..a5c3740b677f1
--- /dev/null
+++ b/tests/baselines/reference/await_unaryExpression_es6_1.types
@@ -0,0 +1,46 @@
+=== tests/cases/conformance/async/es6/await_unaryExpression_es6_1.ts ===
+
+async function bar() {
+>bar : () => Promise<void>
+
+    !await 42; // OK
+>!await 42 : boolean
+>await 42 : number
+>42 : number
+}
+
+async function bar1() {
+>bar1 : () => Promise<void>
+
+    delete await 42; // OK
+>delete await 42 : boolean
+>await 42 : number
+>42 : number
+}
+
+async function bar2() {
+>bar2 : () => Promise<void>
+
+    delete await 42; // OK
+>delete await 42 : boolean
+>await 42 : number
+>42 : number
+}
+
+async function bar3() {
+>bar3 : () => Promise<void>
+
+    void await 42;
+>void await 42 : undefined
+>await 42 : number
+>42 : number
+}
+
+async function bar4() {
+>bar4 : () => Promise<void>
+
+    +await 42;
+>+await 42 : number
+>await 42 : number
+>42 : number
+}
diff --git a/tests/baselines/reference/await_unaryExpression_es6_2.js b/tests/baselines/reference/await_unaryExpression_es6_2.js
new file mode 100644
index 0000000000000..3c341018ed16c
--- /dev/null
+++ b/tests/baselines/reference/await_unaryExpression_es6_2.js
@@ -0,0 +1,38 @@
+//// [await_unaryExpression_es6_2.ts]
+
+async function bar1() {
+    delete await 42;
+}
+
+async function bar2() {
+    delete await 42;
+}
+
+async function bar3() {
+    void await 42;
+}
+
+//// [await_unaryExpression_es6_2.js]
+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());
+    });
+};
+function bar1() {
+    return __awaiter(this, void 0, void 0, function* () {
+        delete (yield 42);
+    });
+}
+function bar2() {
+    return __awaiter(this, void 0, void 0, function* () {
+        delete (yield 42);
+    });
+}
+function bar3() {
+    return __awaiter(this, void 0, void 0, function* () {
+        void (yield 42);
+    });
+}
diff --git a/tests/baselines/reference/await_unaryExpression_es6_2.symbols b/tests/baselines/reference/await_unaryExpression_es6_2.symbols
new file mode 100644
index 0000000000000..574ea4d433a7a
--- /dev/null
+++ b/tests/baselines/reference/await_unaryExpression_es6_2.symbols
@@ -0,0 +1,19 @@
+=== tests/cases/conformance/async/es6/await_unaryExpression_es6_2.ts ===
+
+async function bar1() {
+>bar1 : Symbol(bar1, Decl(await_unaryExpression_es6_2.ts, 0, 0))
+
+    delete await 42;
+}
+
+async function bar2() {
+>bar2 : Symbol(bar2, Decl(await_unaryExpression_es6_2.ts, 3, 1))
+
+    delete await 42;
+}
+
+async function bar3() {
+>bar3 : Symbol(bar3, Decl(await_unaryExpression_es6_2.ts, 7, 1))
+
+    void await 42;
+}
diff --git a/tests/baselines/reference/await_unaryExpression_es6_2.types b/tests/baselines/reference/await_unaryExpression_es6_2.types
new file mode 100644
index 0000000000000..b438f063add31
--- /dev/null
+++ b/tests/baselines/reference/await_unaryExpression_es6_2.types
@@ -0,0 +1,28 @@
+=== tests/cases/conformance/async/es6/await_unaryExpression_es6_2.ts ===
+
+async function bar1() {
+>bar1 : () => Promise<void>
+
+    delete await 42;
+>delete await 42 : boolean
+>await 42 : number
+>42 : number
+}
+
+async function bar2() {
+>bar2 : () => Promise<void>
+
+    delete await 42;
+>delete await 42 : boolean
+>await 42 : number
+>42 : number
+}
+
+async function bar3() {
+>bar3 : () => Promise<void>
+
+    void await 42;
+>void await 42 : undefined
+>await 42 : number
+>42 : number
+}
diff --git a/tests/baselines/reference/await_unaryExpression_es6_3.errors.txt b/tests/baselines/reference/await_unaryExpression_es6_3.errors.txt
new file mode 100644
index 0000000000000..5518f84983f78
--- /dev/null
+++ b/tests/baselines/reference/await_unaryExpression_es6_3.errors.txt
@@ -0,0 +1,27 @@
+tests/cases/conformance/async/es6/await_unaryExpression_es6_3.ts(3,7): error TS1109: Expression expected.
+tests/cases/conformance/async/es6/await_unaryExpression_es6_3.ts(7,7): error TS1109: Expression expected.
+
+
+==== tests/cases/conformance/async/es6/await_unaryExpression_es6_3.ts (2 errors) ====
+    
+    async function bar1() {
+        ++await 42; // Error
+          ~~~~~
+!!! error TS1109: Expression expected.
+    }
+    
+    async function bar2() {
+        --await 42; // Error
+          ~~~~~
+!!! error TS1109: Expression expected.
+    }
+    
+    async function bar3() {
+        var x = 42;
+        await x++; // OK but shouldn't need parenthesis
+    }
+    
+    async function bar4() {
+        var x = 42;
+        await x--; // OK but shouldn't need parenthesis
+    }
\ No newline at end of file
diff --git a/tests/baselines/reference/await_unaryExpression_es6_3.js b/tests/baselines/reference/await_unaryExpression_es6_3.js
new file mode 100644
index 0000000000000..077e264c450e4
--- /dev/null
+++ b/tests/baselines/reference/await_unaryExpression_es6_3.js
@@ -0,0 +1,53 @@
+//// [await_unaryExpression_es6_3.ts]
+
+async function bar1() {
+    ++await 42; // Error
+}
+
+async function bar2() {
+    --await 42; // Error
+}
+
+async function bar3() {
+    var x = 42;
+    await x++; // OK but shouldn't need parenthesis
+}
+
+async function bar4() {
+    var x = 42;
+    await x--; // OK but shouldn't need parenthesis
+}
+
+//// [await_unaryExpression_es6_3.js]
+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());
+    });
+};
+function bar1() {
+    return __awaiter(this, void 0, void 0, function* () {
+        ++;
+        yield 42; // Error
+    });
+}
+function bar2() {
+    return __awaiter(this, void 0, void 0, function* () {
+        --;
+        yield 42; // Error
+    });
+}
+function bar3() {
+    return __awaiter(this, void 0, void 0, function* () {
+        var x = 42;
+        yield x++; // OK but shouldn't need parenthesis
+    });
+}
+function bar4() {
+    return __awaiter(this, void 0, void 0, function* () {
+        var x = 42;
+        yield x--; // OK but shouldn't need parenthesis
+    });
+}
diff --git a/tests/baselines/reference/castOfAwait.js b/tests/baselines/reference/castOfAwait.js
index 95817b7f0e604..26e9812bf431e 100644
--- a/tests/baselines/reference/castOfAwait.js
+++ b/tests/baselines/reference/castOfAwait.js
@@ -20,9 +20,9 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, ge
 function f() {
     return __awaiter(this, void 0, void 0, function* () {
         yield 0;
-        typeof yield 0;
-        void yield 0;
-        yield void typeof void yield 0;
+        typeof (yield 0);
+        void (yield 0);
+        yield void typeof void (yield 0);
         yield yield 0;
     });
 }
diff --git a/tests/cases/conformance/async/es6/await_unaryExpression_es6.ts b/tests/cases/conformance/async/es6/await_unaryExpression_es6.ts
new file mode 100644
index 0000000000000..09cf0a87a5adc
--- /dev/null
+++ b/tests/cases/conformance/async/es6/await_unaryExpression_es6.ts
@@ -0,0 +1,17 @@
+// @target: es6
+
+async function bar() {
+    !await 42; // OK
+}
+
+async function bar1() {
+    +await 42; // OK
+}
+
+async function bar3() {
+    -await 42; // OK
+}
+
+async function bar4() {
+    ~await 42; // OK
+}
\ No newline at end of file
diff --git a/tests/cases/conformance/async/es6/await_unaryExpression_es6_1.ts b/tests/cases/conformance/async/es6/await_unaryExpression_es6_1.ts
new file mode 100644
index 0000000000000..5ccf1a1c35a87
--- /dev/null
+++ b/tests/cases/conformance/async/es6/await_unaryExpression_es6_1.ts
@@ -0,0 +1,21 @@
+// @target: es6
+
+async function bar() {
+    !await 42; // OK
+}
+
+async function bar1() {
+    delete await 42; // OK
+}
+
+async function bar2() {
+    delete await 42; // OK
+}
+
+async function bar3() {
+    void await 42;
+}
+
+async function bar4() {
+    +await 42;
+}
\ No newline at end of file
diff --git a/tests/cases/conformance/async/es6/await_unaryExpression_es6_2.ts b/tests/cases/conformance/async/es6/await_unaryExpression_es6_2.ts
new file mode 100644
index 0000000000000..24683765d1996
--- /dev/null
+++ b/tests/cases/conformance/async/es6/await_unaryExpression_es6_2.ts
@@ -0,0 +1,13 @@
+// @target: es6
+
+async function bar1() {
+    delete await 42;
+}
+
+async function bar2() {
+    delete await 42;
+}
+
+async function bar3() {
+    void await 42;
+}
\ No newline at end of file
diff --git a/tests/cases/conformance/async/es6/await_unaryExpression_es6_3.ts b/tests/cases/conformance/async/es6/await_unaryExpression_es6_3.ts
new file mode 100644
index 0000000000000..b595ab5e748ad
--- /dev/null
+++ b/tests/cases/conformance/async/es6/await_unaryExpression_es6_3.ts
@@ -0,0 +1,19 @@
+// @target: es6
+
+async function bar1() {
+    ++await 42; // Error
+}
+
+async function bar2() {
+    --await 42; // Error
+}
+
+async function bar3() {
+    var x = 42;
+    await x++; // OK but shouldn't need parenthesis
+}
+
+async function bar4() {
+    var x = 42;
+    await x--; // OK but shouldn't need parenthesis
+}
\ No newline at end of file