diff --git a/tests/baselines/reference/defaultExportsCannotMerge01.errors.txt b/tests/baselines/reference/defaultExportsCannotMerge01.errors.txt
new file mode 100644
index 00000000000..6eece36e077
--- /dev/null
+++ b/tests/baselines/reference/defaultExportsCannotMerge01.errors.txt
@@ -0,0 +1,43 @@
+tests/cases/conformance/es6/modules/m2.ts(5,8): error TS2304: Cannot find name 'Entity'.
+tests/cases/conformance/es6/modules/m2.ts(6,8): error TS2503: Cannot find namespace 'Entity'.
+tests/cases/conformance/es6/modules/m2.ts(8,8): error TS2339: Property 'x' does not exist on type '() => number'.
+tests/cases/conformance/es6/modules/m2.ts(9,8): error TS2339: Property 'y' does not exist on type '() => number'.
+
+
+==== tests/cases/conformance/es6/modules/m1.ts (0 errors) ====
+    
+    export default function Decl() {
+        return 0;
+    }
+    
+    export interface Decl {
+        p1: number;
+        p2: number;
+    }
+    
+    export namespace Decl {
+        export var x = 10;
+        export var y = 20;
+    
+        interface I {
+        }
+    }
+    
+==== tests/cases/conformance/es6/modules/m2.ts (4 errors) ====
+    import Entity from "m1"
+    
+    Entity();
+    
+    var x: Entity;
+           ~~~~~~
+!!! error TS2304: Cannot find name 'Entity'.
+    var y: Entity.I;
+           ~~~~~~
+!!! error TS2503: Cannot find namespace 'Entity'.
+    
+    Entity.x;
+           ~
+!!! error TS2339: Property 'x' does not exist on type '() => number'.
+    Entity.y;
+           ~
+!!! error TS2339: Property 'y' does not exist on type '() => number'.
\ No newline at end of file
diff --git a/tests/baselines/reference/defaultExportsCannotMerge01.js b/tests/baselines/reference/defaultExportsCannotMerge01.js
new file mode 100644
index 00000000000..3e0a61d54d4
--- /dev/null
+++ b/tests/baselines/reference/defaultExportsCannotMerge01.js
@@ -0,0 +1,49 @@
+//// [tests/cases/conformance/es6/modules/defaultExportsCannotMerge01.ts] ////
+
+//// [m1.ts]
+
+export default function Decl() {
+    return 0;
+}
+
+export interface Decl {
+    p1: number;
+    p2: number;
+}
+
+export namespace Decl {
+    export var x = 10;
+    export var y = 20;
+
+    interface I {
+    }
+}
+
+//// [m2.ts]
+import Entity from "m1"
+
+Entity();
+
+var x: Entity;
+var y: Entity.I;
+
+Entity.x;
+Entity.y;
+
+//// [m1.js]
+function Decl() {
+    return 0;
+}
+exports.default = Decl;
+var Decl;
+(function (Decl) {
+    Decl.x = 10;
+    Decl.y = 20;
+})(Decl = exports.Decl || (exports.Decl = {}));
+//// [m2.js]
+var m1_1 = require("m1");
+m1_1.default();
+var x;
+var y;
+m1_1.default.x;
+m1_1.default.y;
diff --git a/tests/baselines/reference/defaultExportsCannotMerge02.errors.txt b/tests/baselines/reference/defaultExportsCannotMerge02.errors.txt
new file mode 100644
index 00000000000..7b49afe1a4e
--- /dev/null
+++ b/tests/baselines/reference/defaultExportsCannotMerge02.errors.txt
@@ -0,0 +1,31 @@
+tests/cases/conformance/es6/modules/m1.ts(2,22): error TS2300: Duplicate identifier 'foo'.
+tests/cases/conformance/es6/modules/m1.ts(6,25): error TS2300: Duplicate identifier 'bar'.
+tests/cases/conformance/es6/modules/m1.ts(11,1): error TS2300: Duplicate identifier 'default'.
+tests/cases/conformance/es6/modules/m2.ts(3,1): error TS2348: Value of type 'typeof foo' is not callable. Did you mean to include 'new'?
+
+
+==== tests/cases/conformance/es6/modules/m1.ts (3 errors) ====
+    
+    export default class foo {
+                         ~~~
+!!! error TS2300: Duplicate identifier 'foo'.
+    
+    }
+    
+    export default function bar() {
+                            ~~~
+!!! error TS2300: Duplicate identifier 'bar'.
+    
+    }
+    
+    var x = 10;
+    export default x;
+    ~~~~~~~~~~~~~~~~~
+!!! error TS2300: Duplicate identifier 'default'.
+    
+==== tests/cases/conformance/es6/modules/m2.ts (1 errors) ====
+    import Entity from "m1"
+    
+    Entity();
+    ~~~~~~~~
+!!! error TS2348: Value of type 'typeof foo' is not callable. Did you mean to include 'new'?
\ No newline at end of file
diff --git a/tests/baselines/reference/defaultExportsCannotMerge02.js b/tests/baselines/reference/defaultExportsCannotMerge02.js
new file mode 100644
index 00000000000..54d4e284c71
--- /dev/null
+++ b/tests/baselines/reference/defaultExportsCannotMerge02.js
@@ -0,0 +1,35 @@
+//// [tests/cases/conformance/es6/modules/defaultExportsCannotMerge02.ts] ////
+
+//// [m1.ts]
+
+export default class foo {
+
+}
+
+export default function bar() {
+
+}
+
+var x = 10;
+export default x;
+
+//// [m2.ts]
+import Entity from "m1"
+
+Entity();
+
+//// [m1.js]
+var foo = (function () {
+    function foo() {
+    }
+    return foo;
+})();
+exports.default = foo;
+function bar() {
+}
+exports.default = bar;
+var x = 10;
+exports.default = x;
+//// [m2.js]
+var m1_1 = require("m1");
+m1_1.default();
diff --git a/tests/baselines/reference/defaultExportsCannotMerge03.errors.txt b/tests/baselines/reference/defaultExportsCannotMerge03.errors.txt
new file mode 100644
index 00000000000..51220ecfae2
--- /dev/null
+++ b/tests/baselines/reference/defaultExportsCannotMerge03.errors.txt
@@ -0,0 +1,22 @@
+tests/cases/conformance/es6/modules/m1.ts(2,25): error TS2393: Duplicate function implementation.
+tests/cases/conformance/es6/modules/m1.ts(6,25): error TS2393: Duplicate function implementation.
+
+
+==== tests/cases/conformance/es6/modules/m1.ts (2 errors) ====
+    
+    export default function foo() {
+                            ~~~
+!!! error TS2393: Duplicate function implementation.
+    
+    }
+    
+    export default function bar() {
+                            ~~~
+!!! error TS2393: Duplicate function implementation.
+    
+    }
+    
+==== tests/cases/conformance/es6/modules/m2.ts (0 errors) ====
+    import Entity from "m1"
+    
+    Entity();
\ No newline at end of file
diff --git a/tests/baselines/reference/defaultExportsCannotMerge03.js b/tests/baselines/reference/defaultExportsCannotMerge03.js
new file mode 100644
index 00000000000..cf9003a97c8
--- /dev/null
+++ b/tests/baselines/reference/defaultExportsCannotMerge03.js
@@ -0,0 +1,27 @@
+//// [tests/cases/conformance/es6/modules/defaultExportsCannotMerge03.ts] ////
+
+//// [m1.ts]
+
+export default function foo() {
+
+}
+
+export default function bar() {
+
+}
+
+//// [m2.ts]
+import Entity from "m1"
+
+Entity();
+
+//// [m1.js]
+function foo() {
+}
+exports.default = foo;
+function bar() {
+}
+exports.default = bar;
+//// [m2.js]
+var m1_1 = require("m1");
+m1_1.default();