diff --git a/modules/ve/test/ve.test.js b/modules/ve/test/ve.test.js
index a48a1d0100..1ddab76291 100644
--- a/modules/ve/test/ve.test.js
+++ b/modules/ve/test/ve.test.js
@@ -9,37 +9,6 @@ QUnit.module( 've' );
 
 /* Tests */
 
-// ve.createObject: Tested upstream (JavaScript)
-
-// ve.inheritClass: Tested upstream (OOJS)
-
-// ve.mixinClass: Tested upstream (OOJS)
-
-QUnit.test( 'isMixedIn', 11, function ( assert ) {
-	function Foo () {}
-	function Bar () {}
-	function Quux () {}
-
-	ve.inheritClass( Quux, Foo );
-	ve.mixinClass( Quux, Bar );
-
-	var b = new Bar(),
-		q = new Quux();
-
-	assert.strictEqual( ve.isMixedIn( Foo, Function ), false, 'Direct native inheritance is not considered' );
-	assert.strictEqual( ve.isMixedIn( Foo, Object ), false, 'Indirect native inheritance is not considered' );
-	assert.strictEqual( ve.isMixedIn( Quux, Foo ), false, 've.inheritClass does not affect mixin status' );
-	assert.strictEqual( ve.isMixedIn( Foo, Foo ), false, 'Foo does not mixin Foo' );
-	assert.strictEqual( ve.isMixedIn( Bar, Foo ), false, 'Bar does not mixin Foo' );
-	assert.strictEqual( ve.isMixedIn( Quux, Bar ), true, 'Quux has Bar mixed in' );
-	assert.strictEqual( ve.isMixedIn( Bar, Quux ), false, 'Bar does not mixin Quux' );
-
-	assert.strictEqual( ve.isMixedIn( q, Foo ), false, 've.inheritClass does not affect mixin status' );
-	assert.strictEqual( ve.isMixedIn( b, Foo ), false, 'b does not mixin Foo' );
-	assert.strictEqual( ve.isMixedIn( q, Bar ), true, 'q has Bar mixed in' );
-	assert.strictEqual( ve.isMixedIn( b, Quux ), false, 'b does not mixin Quux' );
-} );
-
 // ve.cloneObject: Tested upstream (OOJS)
 
 // ve.getObjectValues: Tested upstream (OOJS)
diff --git a/modules/ve/ve.js b/modules/ve/ve.js
index 9365984530..782067eddc 100644
--- a/modules/ve/ve.js
+++ b/modules/ve/ve.js
@@ -62,28 +62,7 @@
 	 * @method
 	 * @inheritdoc OO#mixinClass
 	 */
-	ve.mixinClass = function ( targetFn, originFn ) {
-		oo.mixinClass( targetFn, originFn );
-
-		// Track mixins
-		targetFn.mixins = targetFn.mixins || [];
-		targetFn.mixins.push( originFn );
-	};
-
-	/**
-	 * Check if a constructor or object contains a certain mixin.
-	 *
-	 * @param {Function|Object} a Class or object to check
-	 * @param {Function} mixin Mixin to check for
-	 * @returns {boolean} Class or object uses mixin
-	 */
-	ve.isMixedIn = function ( subject, mixin ) {
-		// Traverse from instances to the constructor
-		if ( $.type( subject ) !== 'function' ) {
-			subject = subject.constructor;
-		}
-		return !!subject.mixins && subject.mixins.indexOf( mixin ) !== -1;
-	};
+	ve.mixinClass = oo.mixinClass;
 
 	/**
 	 * @method