diff --git a/js/Disposable.ts b/js/Disposable.ts
index 011945a4..e4c61752 100644
--- a/js/Disposable.ts
+++ b/js/Disposable.ts
@@ -22,7 +22,8 @@ class Disposable {
   public readonly _disposeEmitter: TEmitter = new TinyEmitter();
   public isDisposed = false;
 
-  public constructor() {
+  // Disposable should only be used by subtypes, no need to instantiate one on its own.
+  protected constructor() {
     if ( assert ) {
 
       // Wrap the prototype dispose method with a check. NOTE: We will not catch devious cases where the dispose() is
diff --git a/js/DisposableTests.ts b/js/DisposableTests.ts
index 58ac3bec..9967dd01 100644
--- a/js/DisposableTests.ts
+++ b/js/DisposableTests.ts
@@ -13,9 +13,13 @@ QUnit.module( 'Disposable' );
 QUnit.test( 'Disposable basics', assert => {
   assert.ok( true, 'initial test' );
 
-  const object1 = new Disposable();
+  class MyDisposable extends Disposable {
+    public constructor() { super();}
+  }
+
+  const object1 = new MyDisposable();
   assert.ok( !!object1.disposeEmitter, 'disposeEmitter needed' );
-  const object2 = new Disposable();
+  const object2 = new MyDisposable();
   object1.disposeEmitter.addListener( () => object2.dispose() );
 
   assert.ok( !object1.isDisposed, '1 is not disposed' );