diff --git a/tests/baselines/reference/optionalMethods.js b/tests/baselines/reference/optionalMethods.js
new file mode 100644
index 0000000000..1cf09a588a
--- /dev/null
+++ b/tests/baselines/reference/optionalMethods.js
@@ -0,0 +1,76 @@
+//// [optionalMethods.ts]
+
+interface Foo {
+    a: number;
+    b?: number;
+    f(): number;
+    g?(): number;
+}
+
+function test1(x: Foo) {
+    x.a;
+    x.b;
+    x.f;
+    x.g;
+    let f1 = x.f();
+    let g1 = x.g && x.g();
+    let g2 = x.g ? x.g() : 0;
+}
+
+class Bar {
+    a: number;
+    b?: number;
+    f() {
+        return 1;
+    }
+    g?(): number;  // Body of optional method can be omitted
+    h?() {
+        return 2;
+    }
+}
+
+function test2(x: Bar) {
+    x.a;
+    x.b;
+    x.f;
+    x.g;
+    let f1 = x.f();
+    let g1 = x.g && x.g();
+    let g2 = x.g ? x.g() : 0;
+    let h1 = x.h && x.h();
+    let h2 = x.h ? x.h() : 0;
+}
+
+
+//// [optionalMethods.js]
+function test1(x) {
+    x.a;
+    x.b;
+    x.f;
+    x.g;
+    var f1 = x.f();
+    var g1 = x.g && x.g();
+    var g2 = x.g ? x.g() : 0;
+}
+var Bar = (function () {
+    function Bar() {
+    }
+    Bar.prototype.f = function () {
+        return 1;
+    };
+    Bar.prototype.h = function () {
+        return 2;
+    };
+    return Bar;
+}());
+function test2(x) {
+    x.a;
+    x.b;
+    x.f;
+    x.g;
+    var f1 = x.f();
+    var g1 = x.g && x.g();
+    var g2 = x.g ? x.g() : 0;
+    var h1 = x.h && x.h();
+    var h2 = x.h ? x.h() : 0;
+}
diff --git a/tests/baselines/reference/optionalMethods.symbols b/tests/baselines/reference/optionalMethods.symbols
new file mode 100644
index 0000000000..6b06e1902f
--- /dev/null
+++ b/tests/baselines/reference/optionalMethods.symbols
@@ -0,0 +1,160 @@
+=== tests/cases/conformance/types/namedTypes/optionalMethods.ts ===
+
+interface Foo {
+>Foo : Symbol(Foo, Decl(optionalMethods.ts, 0, 0))
+
+    a: number;
+>a : Symbol(Foo.a, Decl(optionalMethods.ts, 1, 15))
+
+    b?: number;
+>b : Symbol(Foo.b, Decl(optionalMethods.ts, 2, 14))
+
+    f(): number;
+>f : Symbol(Foo.f, Decl(optionalMethods.ts, 3, 15))
+
+    g?(): number;
+>g : Symbol(Foo.g, Decl(optionalMethods.ts, 4, 16))
+}
+
+function test1(x: Foo) {
+>test1 : Symbol(test1, Decl(optionalMethods.ts, 6, 1))
+>x : Symbol(x, Decl(optionalMethods.ts, 8, 15))
+>Foo : Symbol(Foo, Decl(optionalMethods.ts, 0, 0))
+
+    x.a;
+>x.a : Symbol(Foo.a, Decl(optionalMethods.ts, 1, 15))
+>x : Symbol(x, Decl(optionalMethods.ts, 8, 15))
+>a : Symbol(Foo.a, Decl(optionalMethods.ts, 1, 15))
+
+    x.b;
+>x.b : Symbol(Foo.b, Decl(optionalMethods.ts, 2, 14))
+>x : Symbol(x, Decl(optionalMethods.ts, 8, 15))
+>b : Symbol(Foo.b, Decl(optionalMethods.ts, 2, 14))
+
+    x.f;
+>x.f : Symbol(Foo.f, Decl(optionalMethods.ts, 3, 15))
+>x : Symbol(x, Decl(optionalMethods.ts, 8, 15))
+>f : Symbol(Foo.f, Decl(optionalMethods.ts, 3, 15))
+
+    x.g;
+>x.g : Symbol(Foo.g, Decl(optionalMethods.ts, 4, 16))
+>x : Symbol(x, Decl(optionalMethods.ts, 8, 15))
+>g : Symbol(Foo.g, Decl(optionalMethods.ts, 4, 16))
+
+    let f1 = x.f();
+>f1 : Symbol(f1, Decl(optionalMethods.ts, 13, 7))
+>x.f : Symbol(Foo.f, Decl(optionalMethods.ts, 3, 15))
+>x : Symbol(x, Decl(optionalMethods.ts, 8, 15))
+>f : Symbol(Foo.f, Decl(optionalMethods.ts, 3, 15))
+
+    let g1 = x.g && x.g();
+>g1 : Symbol(g1, Decl(optionalMethods.ts, 14, 7))
+>x.g : Symbol(Foo.g, Decl(optionalMethods.ts, 4, 16))
+>x : Symbol(x, Decl(optionalMethods.ts, 8, 15))
+>g : Symbol(Foo.g, Decl(optionalMethods.ts, 4, 16))
+>x.g : Symbol(Foo.g, Decl(optionalMethods.ts, 4, 16))
+>x : Symbol(x, Decl(optionalMethods.ts, 8, 15))
+>g : Symbol(Foo.g, Decl(optionalMethods.ts, 4, 16))
+
+    let g2 = x.g ? x.g() : 0;
+>g2 : Symbol(g2, Decl(optionalMethods.ts, 15, 7))
+>x.g : Symbol(Foo.g, Decl(optionalMethods.ts, 4, 16))
+>x : Symbol(x, Decl(optionalMethods.ts, 8, 15))
+>g : Symbol(Foo.g, Decl(optionalMethods.ts, 4, 16))
+>x.g : Symbol(Foo.g, Decl(optionalMethods.ts, 4, 16))
+>x : Symbol(x, Decl(optionalMethods.ts, 8, 15))
+>g : Symbol(Foo.g, Decl(optionalMethods.ts, 4, 16))
+}
+
+class Bar {
+>Bar : Symbol(Bar, Decl(optionalMethods.ts, 16, 1))
+
+    a: number;
+>a : Symbol(Bar.a, Decl(optionalMethods.ts, 18, 11))
+
+    b?: number;
+>b : Symbol(Bar.b, Decl(optionalMethods.ts, 19, 14))
+
+    f() {
+>f : Symbol(Bar.f, Decl(optionalMethods.ts, 20, 15))
+
+        return 1;
+    }
+    g?(): number;  // Body of optional method can be omitted
+>g : Symbol(Bar.g, Decl(optionalMethods.ts, 23, 5))
+
+    h?() {
+>h : Symbol(Bar.h, Decl(optionalMethods.ts, 24, 17))
+
+        return 2;
+    }
+}
+
+function test2(x: Bar) {
+>test2 : Symbol(test2, Decl(optionalMethods.ts, 28, 1))
+>x : Symbol(x, Decl(optionalMethods.ts, 30, 15))
+>Bar : Symbol(Bar, Decl(optionalMethods.ts, 16, 1))
+
+    x.a;
+>x.a : Symbol(Bar.a, Decl(optionalMethods.ts, 18, 11))
+>x : Symbol(x, Decl(optionalMethods.ts, 30, 15))
+>a : Symbol(Bar.a, Decl(optionalMethods.ts, 18, 11))
+
+    x.b;
+>x.b : Symbol(Bar.b, Decl(optionalMethods.ts, 19, 14))
+>x : Symbol(x, Decl(optionalMethods.ts, 30, 15))
+>b : Symbol(Bar.b, Decl(optionalMethods.ts, 19, 14))
+
+    x.f;
+>x.f : Symbol(Bar.f, Decl(optionalMethods.ts, 20, 15))
+>x : Symbol(x, Decl(optionalMethods.ts, 30, 15))
+>f : Symbol(Bar.f, Decl(optionalMethods.ts, 20, 15))
+
+    x.g;
+>x.g : Symbol(Bar.g, Decl(optionalMethods.ts, 23, 5))
+>x : Symbol(x, Decl(optionalMethods.ts, 30, 15))
+>g : Symbol(Bar.g, Decl(optionalMethods.ts, 23, 5))
+
+    let f1 = x.f();
+>f1 : Symbol(f1, Decl(optionalMethods.ts, 35, 7))
+>x.f : Symbol(Bar.f, Decl(optionalMethods.ts, 20, 15))
+>x : Symbol(x, Decl(optionalMethods.ts, 30, 15))
+>f : Symbol(Bar.f, Decl(optionalMethods.ts, 20, 15))
+
+    let g1 = x.g && x.g();
+>g1 : Symbol(g1, Decl(optionalMethods.ts, 36, 7))
+>x.g : Symbol(Bar.g, Decl(optionalMethods.ts, 23, 5))
+>x : Symbol(x, Decl(optionalMethods.ts, 30, 15))
+>g : Symbol(Bar.g, Decl(optionalMethods.ts, 23, 5))
+>x.g : Symbol(Bar.g, Decl(optionalMethods.ts, 23, 5))
+>x : Symbol(x, Decl(optionalMethods.ts, 30, 15))
+>g : Symbol(Bar.g, Decl(optionalMethods.ts, 23, 5))
+
+    let g2 = x.g ? x.g() : 0;
+>g2 : Symbol(g2, Decl(optionalMethods.ts, 37, 7))
+>x.g : Symbol(Bar.g, Decl(optionalMethods.ts, 23, 5))
+>x : Symbol(x, Decl(optionalMethods.ts, 30, 15))
+>g : Symbol(Bar.g, Decl(optionalMethods.ts, 23, 5))
+>x.g : Symbol(Bar.g, Decl(optionalMethods.ts, 23, 5))
+>x : Symbol(x, Decl(optionalMethods.ts, 30, 15))
+>g : Symbol(Bar.g, Decl(optionalMethods.ts, 23, 5))
+
+    let h1 = x.h && x.h();
+>h1 : Symbol(h1, Decl(optionalMethods.ts, 38, 7))
+>x.h : Symbol(Bar.h, Decl(optionalMethods.ts, 24, 17))
+>x : Symbol(x, Decl(optionalMethods.ts, 30, 15))
+>h : Symbol(Bar.h, Decl(optionalMethods.ts, 24, 17))
+>x.h : Symbol(Bar.h, Decl(optionalMethods.ts, 24, 17))
+>x : Symbol(x, Decl(optionalMethods.ts, 30, 15))
+>h : Symbol(Bar.h, Decl(optionalMethods.ts, 24, 17))
+
+    let h2 = x.h ? x.h() : 0;
+>h2 : Symbol(h2, Decl(optionalMethods.ts, 39, 7))
+>x.h : Symbol(Bar.h, Decl(optionalMethods.ts, 24, 17))
+>x : Symbol(x, Decl(optionalMethods.ts, 30, 15))
+>h : Symbol(Bar.h, Decl(optionalMethods.ts, 24, 17))
+>x.h : Symbol(Bar.h, Decl(optionalMethods.ts, 24, 17))
+>x : Symbol(x, Decl(optionalMethods.ts, 30, 15))
+>h : Symbol(Bar.h, Decl(optionalMethods.ts, 24, 17))
+}
+
diff --git a/tests/baselines/reference/optionalMethods.types b/tests/baselines/reference/optionalMethods.types
new file mode 100644
index 0000000000..528a2e2354
--- /dev/null
+++ b/tests/baselines/reference/optionalMethods.types
@@ -0,0 +1,179 @@
+=== tests/cases/conformance/types/namedTypes/optionalMethods.ts ===
+
+interface Foo {
+>Foo : Foo
+
+    a: number;
+>a : number
+
+    b?: number;
+>b : number | undefined
+
+    f(): number;
+>f : () => number
+
+    g?(): number;
+>g : (() => number) | undefined
+}
+
+function test1(x: Foo) {
+>test1 : (x: Foo) => void
+>x : Foo
+>Foo : Foo
+
+    x.a;
+>x.a : number
+>x : Foo
+>a : number
+
+    x.b;
+>x.b : number | undefined
+>x : Foo
+>b : number | undefined
+
+    x.f;
+>x.f : () => number
+>x : Foo
+>f : () => number
+
+    x.g;
+>x.g : (() => number) | undefined
+>x : Foo
+>g : (() => number) | undefined
+
+    let f1 = x.f();
+>f1 : number
+>x.f() : number
+>x.f : () => number
+>x : Foo
+>f : () => number
+
+    let g1 = x.g && x.g();
+>g1 : number | undefined
+>x.g && x.g() : number | undefined
+>x.g : (() => number) | undefined
+>x : Foo
+>g : (() => number) | undefined
+>x.g() : number
+>x.g : () => number
+>x : Foo
+>g : () => number
+
+    let g2 = x.g ? x.g() : 0;
+>g2 : number
+>x.g ? x.g() : 0 : number
+>x.g : (() => number) | undefined
+>x : Foo
+>g : (() => number) | undefined
+>x.g() : number
+>x.g : () => number
+>x : Foo
+>g : () => number
+>0 : number
+}
+
+class Bar {
+>Bar : Bar
+
+    a: number;
+>a : number
+
+    b?: number;
+>b : number | undefined
+
+    f() {
+>f : () => number
+
+        return 1;
+>1 : number
+    }
+    g?(): number;  // Body of optional method can be omitted
+>g : (() => number) | undefined
+
+    h?() {
+>h : (() => number) | undefined
+
+        return 2;
+>2 : number
+    }
+}
+
+function test2(x: Bar) {
+>test2 : (x: Bar) => void
+>x : Bar
+>Bar : Bar
+
+    x.a;
+>x.a : number
+>x : Bar
+>a : number
+
+    x.b;
+>x.b : number | undefined
+>x : Bar
+>b : number | undefined
+
+    x.f;
+>x.f : () => number
+>x : Bar
+>f : () => number
+
+    x.g;
+>x.g : (() => number) | undefined
+>x : Bar
+>g : (() => number) | undefined
+
+    let f1 = x.f();
+>f1 : number
+>x.f() : number
+>x.f : () => number
+>x : Bar
+>f : () => number
+
+    let g1 = x.g && x.g();
+>g1 : number | undefined
+>x.g && x.g() : number | undefined
+>x.g : (() => number) | undefined
+>x : Bar
+>g : (() => number) | undefined
+>x.g() : number
+>x.g : () => number
+>x : Bar
+>g : () => number
+
+    let g2 = x.g ? x.g() : 0;
+>g2 : number
+>x.g ? x.g() : 0 : number
+>x.g : (() => number) | undefined
+>x : Bar
+>g : (() => number) | undefined
+>x.g() : number
+>x.g : () => number
+>x : Bar
+>g : () => number
+>0 : number
+
+    let h1 = x.h && x.h();
+>h1 : number | undefined
+>x.h && x.h() : number | undefined
+>x.h : (() => number) | undefined
+>x : Bar
+>h : (() => number) | undefined
+>x.h() : number
+>x.h : () => number
+>x : Bar
+>h : () => number
+
+    let h2 = x.h ? x.h() : 0;
+>h2 : number
+>x.h ? x.h() : 0 : number
+>x.h : (() => number) | undefined
+>x : Bar
+>h : (() => number) | undefined
+>x.h() : number
+>x.h : () => number
+>x : Bar
+>h : () => number
+>0 : number
+}
+
diff --git a/tests/cases/conformance/types/namedTypes/optionalMethods.ts b/tests/cases/conformance/types/namedTypes/optionalMethods.ts
new file mode 100644
index 0000000000..47cd72fbae
--- /dev/null
+++ b/tests/cases/conformance/types/namedTypes/optionalMethods.ts
@@ -0,0 +1,42 @@
+// @strictNullChecks: true
+
+interface Foo {
+    a: number;
+    b?: number;
+    f(): number;
+    g?(): number;
+}
+
+function test1(x: Foo) {
+    x.a;
+    x.b;
+    x.f;
+    x.g;
+    let f1 = x.f();
+    let g1 = x.g && x.g();
+    let g2 = x.g ? x.g() : 0;
+}
+
+class Bar {
+    a: number;
+    b?: number;
+    f() {
+        return 1;
+    }
+    g?(): number;  // Body of optional method can be omitted
+    h?() {
+        return 2;
+    }
+}
+
+function test2(x: Bar) {
+    x.a;
+    x.b;
+    x.f;
+    x.g;
+    let f1 = x.f();
+    let g1 = x.g && x.g();
+    let g2 = x.g ? x.g() : 0;
+    let h1 = x.h && x.h();
+    let h2 = x.h ? x.h() : 0;
+}