diff --git a/src/compiler/emitter.ts b/src/compiler/emitter.ts
index 6adf76903fb01..a801effd49af8 100644
--- a/src/compiler/emitter.ts
+++ b/src/compiler/emitter.ts
@@ -2749,7 +2749,7 @@ var __awaiter = (this && this.__awaiter) || function (thisArg, _arguments, P, ge
              *   if we should also export the value after its it changed
              * - check if node is a source level declaration to emit it differently,
              *   i.e non-exported variable statement 'var x = 1' is hoisted so
-             *   we we emit variable statement 'var' should be dropped.
+             *   when we emit variable statement 'var' should be dropped.
              */
             function isSourceFileLevelDeclarationInSystemJsModule(node: Node, isExported: boolean): boolean {
                 if (!node || !isCurrentFileSystemExternalModule()) {
@@ -5503,16 +5503,15 @@ const _super = (function (geti, seti) {
                             write("export ");
                         }
 
-                        if (!isHoistedDeclarationInSystemModule) {
-                            write("let ");
-                        }
                         if (decoratedClassAlias !== undefined) {
-                            write(`${decoratedClassAlias}`);
+                            write(`let ${decoratedClassAlias}`);
                         }
                         else {
+                            if (!isHoistedDeclarationInSystemModule) {
+                                write("let ");
+                            }
                             emitDeclarationName(node);
                         }
-
                         write(" = ");
                     }
                     else if (isES6ExportedDeclaration(node)) {
@@ -5530,7 +5529,9 @@ const _super = (function (geti, seti) {
                 //
                 // We'll emit:
                 //
-                //      (_temp = class C { ... }, _temp.a = 1, _temp.b = 2, _temp)
+                //      let C_1 = class C{};
+                //      C_1.a = 1;
+                //      C_1.b = 2; // so forth and so on
                 //
                 // This keeps the expression as an expression, while ensuring that the static parts
                 // of it have been initialized by the time it is used.
diff --git a/tests/baselines/reference/decoratedClassExportsCommonJS1.js b/tests/baselines/reference/decoratedClassExportsCommonJS1.js
new file mode 100644
index 0000000000000..4a04d724f0c95
--- /dev/null
+++ b/tests/baselines/reference/decoratedClassExportsCommonJS1.js
@@ -0,0 +1,28 @@
+//// [decoratedClassExportsCommonJS1.ts]
+declare var Something: any;
+@Something({ v: () => Testing123 })
+export class Testing123 {
+    static prop0: string;
+    static prop1 = Testing123.prop0;
+}
+
+//// [decoratedClassExportsCommonJS1.js]
+"use strict";
+var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
+    var c = arguments.length, r = c < 3 ? target : desc === null ? desc = Object.getOwnPropertyDescriptor(target, key) : desc, d;
+    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") r = Reflect.decorate(decorators, target, key, desc);
+    else for (var i = decorators.length - 1; i >= 0; i--) if (d = decorators[i]) r = (c < 3 ? d(r) : c > 3 ? d(target, key, r) : d(target, key)) || r;
+    return c > 3 && r && Object.defineProperty(target, key, r), r;
+};
+var __metadata = (this && this.__metadata) || function (k, v) {
+    if (typeof Reflect === "object" && typeof Reflect.metadata === "function") return Reflect.metadata(k, v);
+};
+let Testing123_1 = class Testing123 {
+};
+let Testing123 = Testing123_1;
+Testing123.prop1 = Testing123.prop0;
+Testing123 = Testing123_1 = __decorate([
+    Something({ v: () => Testing123 }), 
+    __metadata('design:paramtypes', [])
+], Testing123);
+exports.Testing123 = Testing123;
diff --git a/tests/baselines/reference/decoratedClassExportsCommonJS1.symbols b/tests/baselines/reference/decoratedClassExportsCommonJS1.symbols
new file mode 100644
index 0000000000000..3381ef7c06ae5
--- /dev/null
+++ b/tests/baselines/reference/decoratedClassExportsCommonJS1.symbols
@@ -0,0 +1,21 @@
+=== tests/cases/conformance/decorators/class/decoratedClassExportsCommonJS1.ts ===
+declare var Something: any;
+>Something : Symbol(Something, Decl(decoratedClassExportsCommonJS1.ts, 0, 11))
+
+@Something({ v: () => Testing123 })
+>Something : Symbol(Something, Decl(decoratedClassExportsCommonJS1.ts, 0, 11))
+>v : Symbol(v, Decl(decoratedClassExportsCommonJS1.ts, 1, 12))
+>Testing123 : Symbol(Testing123, Decl(decoratedClassExportsCommonJS1.ts, 0, 27))
+
+export class Testing123 {
+>Testing123 : Symbol(Testing123, Decl(decoratedClassExportsCommonJS1.ts, 0, 27))
+
+    static prop0: string;
+>prop0 : Symbol(Testing123.prop0, Decl(decoratedClassExportsCommonJS1.ts, 2, 25))
+
+    static prop1 = Testing123.prop0;
+>prop1 : Symbol(Testing123.prop1, Decl(decoratedClassExportsCommonJS1.ts, 3, 25))
+>Testing123.prop0 : Symbol(Testing123.prop0, Decl(decoratedClassExportsCommonJS1.ts, 2, 25))
+>Testing123 : Symbol(Testing123, Decl(decoratedClassExportsCommonJS1.ts, 0, 27))
+>prop0 : Symbol(Testing123.prop0, Decl(decoratedClassExportsCommonJS1.ts, 2, 25))
+}
diff --git a/tests/baselines/reference/decoratedClassExportsCommonJS1.types b/tests/baselines/reference/decoratedClassExportsCommonJS1.types
new file mode 100644
index 0000000000000..0142adb654f87
--- /dev/null
+++ b/tests/baselines/reference/decoratedClassExportsCommonJS1.types
@@ -0,0 +1,24 @@
+=== tests/cases/conformance/decorators/class/decoratedClassExportsCommonJS1.ts ===
+declare var Something: any;
+>Something : any
+
+@Something({ v: () => Testing123 })
+>Something({ v: () => Testing123 }) : any
+>Something : any
+>{ v: () => Testing123 } : { v: () => typeof Testing123; }
+>v : () => typeof Testing123
+>() => Testing123 : () => typeof Testing123
+>Testing123 : typeof Testing123
+
+export class Testing123 {
+>Testing123 : Testing123
+
+    static prop0: string;
+>prop0 : string
+
+    static prop1 = Testing123.prop0;
+>prop1 : string
+>Testing123.prop0 : string
+>Testing123 : typeof Testing123
+>prop0 : string
+}
diff --git a/tests/baselines/reference/decoratedClassExportsCommonJS2.js b/tests/baselines/reference/decoratedClassExportsCommonJS2.js
new file mode 100644
index 0000000000000..c5e8eb9aa2981
--- /dev/null
+++ b/tests/baselines/reference/decoratedClassExportsCommonJS2.js
@@ -0,0 +1,26 @@
+//// [a.ts]
+
+declare function forwardRef(x: any): any;
+declare var Something: any;
+@Something({ v: () => Testing123 })
+export class Testing123 { }
+
+//// [a.js]
+"use strict";
+var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
+    var c = arguments.length, r = c < 3 ? target : desc === null ? desc = Object.getOwnPropertyDescriptor(target, key) : desc, d;
+    if (typeof Reflect === "object" && typeof Reflect.decorate === "function") r = Reflect.decorate(decorators, target, key, desc);
+    else for (var i = decorators.length - 1; i >= 0; i--) if (d = decorators[i]) r = (c < 3 ? d(r) : c > 3 ? d(target, key, r) : d(target, key)) || r;
+    return c > 3 && r && Object.defineProperty(target, key, r), r;
+};
+var __metadata = (this && this.__metadata) || function (k, v) {
+    if (typeof Reflect === "object" && typeof Reflect.metadata === "function") return Reflect.metadata(k, v);
+};
+let Testing123_1 = class Testing123 {
+};
+let Testing123 = Testing123_1;
+Testing123 = Testing123_1 = __decorate([
+    Something({ v: () => Testing123 }), 
+    __metadata('design:paramtypes', [])
+], Testing123);
+exports.Testing123 = Testing123;
diff --git a/tests/baselines/reference/decoratedClassExportsCommonJS2.symbols b/tests/baselines/reference/decoratedClassExportsCommonJS2.symbols
new file mode 100644
index 0000000000000..8f587c1bff14d
--- /dev/null
+++ b/tests/baselines/reference/decoratedClassExportsCommonJS2.symbols
@@ -0,0 +1,17 @@
+=== tests/cases/conformance/decorators/class/a.ts ===
+
+declare function forwardRef(x: any): any;
+>forwardRef : Symbol(forwardRef, Decl(a.ts, 0, 0))
+>x : Symbol(x, Decl(a.ts, 1, 28))
+
+declare var Something: any;
+>Something : Symbol(Something, Decl(a.ts, 2, 11))
+
+@Something({ v: () => Testing123 })
+>Something : Symbol(Something, Decl(a.ts, 2, 11))
+>v : Symbol(v, Decl(a.ts, 3, 12))
+>Testing123 : Symbol(Testing123, Decl(a.ts, 2, 27))
+
+export class Testing123 { }
+>Testing123 : Symbol(Testing123, Decl(a.ts, 2, 27))
+
diff --git a/tests/baselines/reference/decoratedClassExportsCommonJS2.types b/tests/baselines/reference/decoratedClassExportsCommonJS2.types
new file mode 100644
index 0000000000000..eba793247de56
--- /dev/null
+++ b/tests/baselines/reference/decoratedClassExportsCommonJS2.types
@@ -0,0 +1,20 @@
+=== tests/cases/conformance/decorators/class/a.ts ===
+
+declare function forwardRef(x: any): any;
+>forwardRef : (x: any) => any
+>x : any
+
+declare var Something: any;
+>Something : any
+
+@Something({ v: () => Testing123 })
+>Something({ v: () => Testing123 }) : any
+>Something : any
+>{ v: () => Testing123 } : { v: () => typeof Testing123; }
+>v : () => typeof Testing123
+>() => Testing123 : () => typeof Testing123
+>Testing123 : typeof Testing123
+
+export class Testing123 { }
+>Testing123 : Testing123
+
diff --git a/tests/baselines/reference/decoratedClassExportsSystem1.js b/tests/baselines/reference/decoratedClassExportsSystem1.js
new file mode 100644
index 0000000000000..1730ba4460f11
--- /dev/null
+++ b/tests/baselines/reference/decoratedClassExportsSystem1.js
@@ -0,0 +1,39 @@
+//// [a.ts]
+
+declare function forwardRef(x: any): any;
+declare var Something: any;
+@Something({ v: () => Testing123 })
+export class Testing123 {
+    static prop0: string;
+    static prop1 = Testing123.prop0;
+}
+
+//// [a.js]
+System.register([], function(exports_1, context_1) {
+    "use strict";
+    var __moduleName = context_1 && context_1.id;
+    var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
+        var c = arguments.length, r = c < 3 ? target : desc === null ? desc = Object.getOwnPropertyDescriptor(target, key) : desc, d;
+        if (typeof Reflect === "object" && typeof Reflect.decorate === "function") r = Reflect.decorate(decorators, target, key, desc);
+        else for (var i = decorators.length - 1; i >= 0; i--) if (d = decorators[i]) r = (c < 3 ? d(r) : c > 3 ? d(target, key, r) : d(target, key)) || r;
+        return c > 3 && r && Object.defineProperty(target, key, r), r;
+    };
+    var __metadata = (this && this.__metadata) || function (k, v) {
+        if (typeof Reflect === "object" && typeof Reflect.metadata === "function") return Reflect.metadata(k, v);
+    };
+    var Testing123;
+    return {
+        setters:[],
+        execute: function() {
+            let Testing123_1 = class Testing123 {
+            };
+            let Testing123 = Testing123_1;
+            Testing123.prop1 = Testing123.prop0;
+            Testing123 = Testing123_1 = __decorate([
+                Something({ v: () => Testing123 }), 
+                __metadata('design:paramtypes', [])
+            ], Testing123);
+            exports_1("Testing123", Testing123);
+        }
+    }
+});
diff --git a/tests/baselines/reference/decoratedClassExportsSystem1.symbols b/tests/baselines/reference/decoratedClassExportsSystem1.symbols
new file mode 100644
index 0000000000000..559f78624e315
--- /dev/null
+++ b/tests/baselines/reference/decoratedClassExportsSystem1.symbols
@@ -0,0 +1,26 @@
+=== tests/cases/conformance/decorators/class/a.ts ===
+
+declare function forwardRef(x: any): any;
+>forwardRef : Symbol(forwardRef, Decl(a.ts, 0, 0))
+>x : Symbol(x, Decl(a.ts, 1, 28))
+
+declare var Something: any;
+>Something : Symbol(Something, Decl(a.ts, 2, 11))
+
+@Something({ v: () => Testing123 })
+>Something : Symbol(Something, Decl(a.ts, 2, 11))
+>v : Symbol(v, Decl(a.ts, 3, 12))
+>Testing123 : Symbol(Testing123, Decl(a.ts, 2, 27))
+
+export class Testing123 {
+>Testing123 : Symbol(Testing123, Decl(a.ts, 2, 27))
+
+    static prop0: string;
+>prop0 : Symbol(Testing123.prop0, Decl(a.ts, 4, 25))
+
+    static prop1 = Testing123.prop0;
+>prop1 : Symbol(Testing123.prop1, Decl(a.ts, 5, 25))
+>Testing123.prop0 : Symbol(Testing123.prop0, Decl(a.ts, 4, 25))
+>Testing123 : Symbol(Testing123, Decl(a.ts, 2, 27))
+>prop0 : Symbol(Testing123.prop0, Decl(a.ts, 4, 25))
+}
diff --git a/tests/baselines/reference/decoratedClassExportsSystem1.types b/tests/baselines/reference/decoratedClassExportsSystem1.types
new file mode 100644
index 0000000000000..1cc69e8b68091
--- /dev/null
+++ b/tests/baselines/reference/decoratedClassExportsSystem1.types
@@ -0,0 +1,29 @@
+=== tests/cases/conformance/decorators/class/a.ts ===
+
+declare function forwardRef(x: any): any;
+>forwardRef : (x: any) => any
+>x : any
+
+declare var Something: any;
+>Something : any
+
+@Something({ v: () => Testing123 })
+>Something({ v: () => Testing123 }) : any
+>Something : any
+>{ v: () => Testing123 } : { v: () => typeof Testing123; }
+>v : () => typeof Testing123
+>() => Testing123 : () => typeof Testing123
+>Testing123 : typeof Testing123
+
+export class Testing123 {
+>Testing123 : Testing123
+
+    static prop0: string;
+>prop0 : string
+
+    static prop1 = Testing123.prop0;
+>prop1 : string
+>Testing123.prop0 : string
+>Testing123 : typeof Testing123
+>prop0 : string
+}
diff --git a/tests/baselines/reference/decoratedClassExportsSystem2.js b/tests/baselines/reference/decoratedClassExportsSystem2.js
new file mode 100644
index 0000000000000..b4d34de2958d9
--- /dev/null
+++ b/tests/baselines/reference/decoratedClassExportsSystem2.js
@@ -0,0 +1,35 @@
+//// [a.ts]
+
+declare function forwardRef(x: any): any;
+declare var Something: any;
+@Something({ v: () => Testing123 })
+export class Testing123 { }
+
+//// [a.js]
+System.register([], function(exports_1, context_1) {
+    "use strict";
+    var __moduleName = context_1 && context_1.id;
+    var __decorate = (this && this.__decorate) || function (decorators, target, key, desc) {
+        var c = arguments.length, r = c < 3 ? target : desc === null ? desc = Object.getOwnPropertyDescriptor(target, key) : desc, d;
+        if (typeof Reflect === "object" && typeof Reflect.decorate === "function") r = Reflect.decorate(decorators, target, key, desc);
+        else for (var i = decorators.length - 1; i >= 0; i--) if (d = decorators[i]) r = (c < 3 ? d(r) : c > 3 ? d(target, key, r) : d(target, key)) || r;
+        return c > 3 && r && Object.defineProperty(target, key, r), r;
+    };
+    var __metadata = (this && this.__metadata) || function (k, v) {
+        if (typeof Reflect === "object" && typeof Reflect.metadata === "function") return Reflect.metadata(k, v);
+    };
+    var Testing123;
+    return {
+        setters:[],
+        execute: function() {
+            let Testing123_1 = class Testing123 {
+            };
+            let Testing123 = Testing123_1;
+            Testing123 = Testing123_1 = __decorate([
+                Something({ v: () => Testing123 }), 
+                __metadata('design:paramtypes', [])
+            ], Testing123);
+            exports_1("Testing123", Testing123);
+        }
+    }
+});
diff --git a/tests/baselines/reference/decoratedClassExportsSystem2.symbols b/tests/baselines/reference/decoratedClassExportsSystem2.symbols
new file mode 100644
index 0000000000000..8f587c1bff14d
--- /dev/null
+++ b/tests/baselines/reference/decoratedClassExportsSystem2.symbols
@@ -0,0 +1,17 @@
+=== tests/cases/conformance/decorators/class/a.ts ===
+
+declare function forwardRef(x: any): any;
+>forwardRef : Symbol(forwardRef, Decl(a.ts, 0, 0))
+>x : Symbol(x, Decl(a.ts, 1, 28))
+
+declare var Something: any;
+>Something : Symbol(Something, Decl(a.ts, 2, 11))
+
+@Something({ v: () => Testing123 })
+>Something : Symbol(Something, Decl(a.ts, 2, 11))
+>v : Symbol(v, Decl(a.ts, 3, 12))
+>Testing123 : Symbol(Testing123, Decl(a.ts, 2, 27))
+
+export class Testing123 { }
+>Testing123 : Symbol(Testing123, Decl(a.ts, 2, 27))
+
diff --git a/tests/baselines/reference/decoratedClassExportsSystem2.types b/tests/baselines/reference/decoratedClassExportsSystem2.types
new file mode 100644
index 0000000000000..eba793247de56
--- /dev/null
+++ b/tests/baselines/reference/decoratedClassExportsSystem2.types
@@ -0,0 +1,20 @@
+=== tests/cases/conformance/decorators/class/a.ts ===
+
+declare function forwardRef(x: any): any;
+>forwardRef : (x: any) => any
+>x : any
+
+declare var Something: any;
+>Something : any
+
+@Something({ v: () => Testing123 })
+>Something({ v: () => Testing123 }) : any
+>Something : any
+>{ v: () => Testing123 } : { v: () => typeof Testing123; }
+>v : () => typeof Testing123
+>() => Testing123 : () => typeof Testing123
+>Testing123 : typeof Testing123
+
+export class Testing123 { }
+>Testing123 : Testing123
+
diff --git a/tests/cases/conformance/decorators/class/decoratedClassExportsCommonJS1.ts b/tests/cases/conformance/decorators/class/decoratedClassExportsCommonJS1.ts
new file mode 100644
index 0000000000000..e00adf3d63b7a
--- /dev/null
+++ b/tests/cases/conformance/decorators/class/decoratedClassExportsCommonJS1.ts
@@ -0,0 +1,13 @@
+// @target: es6
+// @experimentaldecorators: true
+// @emitDecoratorMetadata: true
+// @module: commonjs
+// @filename: a.ts
+
+declare function forwardRef(x: any): any;
+declare var Something: any;
+@Something({ v: () => Testing123 })
+export class Testing123 {
+    static prop0: string;
+    static prop1 = Testing123.prop0;
+}
\ No newline at end of file
diff --git a/tests/cases/conformance/decorators/class/decoratedClassExportsCommonJS2.ts b/tests/cases/conformance/decorators/class/decoratedClassExportsCommonJS2.ts
new file mode 100644
index 0000000000000..38f6ce9f27d8d
--- /dev/null
+++ b/tests/cases/conformance/decorators/class/decoratedClassExportsCommonJS2.ts
@@ -0,0 +1,10 @@
+// @target: es6
+// @experimentaldecorators: true
+// @emitDecoratorMetadata: true
+// @module: commonjs
+// @filename: a.ts
+
+declare function forwardRef(x: any): any;
+declare var Something: any;
+@Something({ v: () => Testing123 })
+export class Testing123 { }
\ No newline at end of file
diff --git a/tests/cases/conformance/decorators/class/decoratedClassExportsSystem1.ts b/tests/cases/conformance/decorators/class/decoratedClassExportsSystem1.ts
new file mode 100644
index 0000000000000..1e2619ab89ef2
--- /dev/null
+++ b/tests/cases/conformance/decorators/class/decoratedClassExportsSystem1.ts
@@ -0,0 +1,13 @@
+// @target: es6
+// @experimentaldecorators: true
+// @emitDecoratorMetadata: true
+// @module: system
+// @filename: a.ts
+
+declare function forwardRef(x: any): any;
+declare var Something: any;
+@Something({ v: () => Testing123 })
+export class Testing123 {
+    static prop0: string;
+    static prop1 = Testing123.prop0;
+}
\ No newline at end of file
diff --git a/tests/cases/conformance/decorators/class/decoratedClassExportsSystem2.ts b/tests/cases/conformance/decorators/class/decoratedClassExportsSystem2.ts
new file mode 100644
index 0000000000000..bf7c9a0ca2deb
--- /dev/null
+++ b/tests/cases/conformance/decorators/class/decoratedClassExportsSystem2.ts
@@ -0,0 +1,10 @@
+// @target: es6
+// @experimentaldecorators: true
+// @emitDecoratorMetadata: true
+// @module: system
+// @filename: a.ts
+
+declare function forwardRef(x: any): any;
+declare var Something: any;
+@Something({ v: () => Testing123 })
+export class Testing123 { }
\ No newline at end of file