diff --git a/tests/cases/compiler/readonlyMembers.ts b/tests/cases/compiler/readonlyMembers.ts
new file mode 100644
index 0000000000..f24b365772
--- /dev/null
+++ b/tests/cases/compiler/readonlyMembers.ts
@@ -0,0 +1,67 @@
+// @target: es5
+
+interface X {
+    readonly a: number;
+    readonly b?: number;
+}
+var x: X = { a: 0 };
+x.a = 1;  // Error
+x.b = 1;  // Error
+
+class C {
+    readonly a: number;
+    readonly b = 1;
+    get c() { return 1 }
+    constructor() {
+        this.a = 1;  // Ok
+        this.b = 1;  // Ok
+        this.c = 1;  // Error
+        const f = () => {
+            this.a = 1;  // Error
+            this.b = 1;  // Error
+            this.c = 1;  // Error
+        }
+    }
+    foo() {
+        this.a = 1;  // Error
+        this.b = 1;  // Error
+        this.c = 1;  // Error
+    }
+}
+
+var o = {
+    get a() { return 1 },
+    get b() { return 1 },
+    set b(value) { }
+};
+o.a = 1;  // Error
+o.b = 1;
+
+var p: { readonly a: number, b: number } = { a: 1, b: 1 };
+p.a = 1;  // Error
+p.b = 1;
+var q: { a: number, b: number } = p;
+q.a = 1;
+q.b = 1;
+
+enum E {
+    A, B, C
+}
+E.A = 1;  // Error
+
+namespace N {
+    export const a = 1;
+    export let b = 1;
+    export var c = 1;
+}
+N.a = 1;  // Error
+N.b = 1;
+N.c = 1;
+
+let xx: { readonly [x: string]: string };
+let s = xx["foo"];
+xx["foo"] = "abc";  // Error
+
+let yy: { readonly [x: number]: string, [x: string]: string };
+yy[1] = "abc";  // Error
+yy["foo"] = "abc";
\ No newline at end of file
diff --git a/tests/cases/conformance/externalModules/importsImplicitlyReadonly.ts b/tests/cases/conformance/externalModules/importsImplicitlyReadonly.ts
new file mode 100644
index 0000000000..f527606e57
--- /dev/null
+++ b/tests/cases/conformance/externalModules/importsImplicitlyReadonly.ts
@@ -0,0 +1,21 @@
+// @module: commonjs
+
+// @filename: a.ts
+export var x = 1;
+var y = 1;
+export { y };
+
+// @filename: b.ts
+import { x, y } from "./a";
+import * as a1 from "./a";
+import a2 = require("./a");
+const a3 = a1;
+
+x = 1;     // Error
+y = 1;     // Error
+a1.x = 1;  // Error
+a1.y = 1;  // Error
+a2.x = 1;
+a2.y = 1;
+a3.x = 1;
+a3.y = 1;
\ No newline at end of file