diff --git a/tests/baselines/reference/declarationEmitParameterProperty.js b/tests/baselines/reference/declarationEmitParameterProperty.js
new file mode 100644
index 00000000000..262222e3c68
--- /dev/null
+++ b/tests/baselines/reference/declarationEmitParameterProperty.js
@@ -0,0 +1,24 @@
+//// [declarationEmitParameterProperty.ts]
+export class Foo {
+  constructor(public bar?: string) {
+  }
+}
+
+
+//// [declarationEmitParameterProperty.js]
+"use strict";
+exports.__esModule = true;
+var Foo = (function () {
+    function Foo(bar) {
+        this.bar = bar;
+    }
+    return Foo;
+}());
+exports.Foo = Foo;
+
+
+//// [declarationEmitParameterProperty.d.ts]
+export declare class Foo {
+    bar: string | undefined;
+    constructor(bar?: string | undefined);
+}
diff --git a/tests/baselines/reference/declarationEmitParameterProperty.symbols b/tests/baselines/reference/declarationEmitParameterProperty.symbols
new file mode 100644
index 00000000000..d9e88e52cb0
--- /dev/null
+++ b/tests/baselines/reference/declarationEmitParameterProperty.symbols
@@ -0,0 +1,9 @@
+=== tests/cases/compiler/declarationEmitParameterProperty.ts ===
+export class Foo {
+>Foo : Symbol(Foo, Decl(declarationEmitParameterProperty.ts, 0, 0))
+
+  constructor(public bar?: string) {
+>bar : Symbol(Foo.bar, Decl(declarationEmitParameterProperty.ts, 1, 14))
+  }
+}
+
diff --git a/tests/baselines/reference/declarationEmitParameterProperty.types b/tests/baselines/reference/declarationEmitParameterProperty.types
new file mode 100644
index 00000000000..3adfecf0c75
--- /dev/null
+++ b/tests/baselines/reference/declarationEmitParameterProperty.types
@@ -0,0 +1,9 @@
+=== tests/cases/compiler/declarationEmitParameterProperty.ts ===
+export class Foo {
+>Foo : Foo
+
+  constructor(public bar?: string) {
+>bar : string | undefined
+  }
+}
+
diff --git a/tests/baselines/reference/optionalMethods.js b/tests/baselines/reference/optionalMethods.js
index d219466c562..2abcd209277 100644
--- a/tests/baselines/reference/optionalMethods.js
+++ b/tests/baselines/reference/optionalMethods.js
@@ -131,12 +131,12 @@ interface Foo {
 }
 declare function test1(x: Foo): void;
 declare class Bar {
-    d: number;
+    d: number | undefined;
     e: number;
     a: number;
     b?: number;
     c?: number | undefined;
-    constructor(d?: number, e?: number);
+    constructor(d?: number | undefined, e?: number);
     f(): number;
     g?(): number;
     h?(): number;
diff --git a/tests/cases/compiler/declarationEmitParameterProperty.ts b/tests/cases/compiler/declarationEmitParameterProperty.ts
new file mode 100644
index 00000000000..107d192fe88
--- /dev/null
+++ b/tests/cases/compiler/declarationEmitParameterProperty.ts
@@ -0,0 +1,6 @@
+// @strictNullChecks: true
+// @declaration: true
+export class Foo {
+  constructor(public bar?: string) {
+  }
+}