diff --git a/src/Illuminate/Routing/SortedMiddleware.php b/src/Illuminate/Routing/SortedMiddleware.php
index 3c2c7912d219..853378cf7e92 100644
--- a/src/Illuminate/Routing/SortedMiddleware.php
+++ b/src/Illuminate/Routing/SortedMiddleware.php
@@ -101,14 +101,6 @@ protected function middlewareNames($middleware)
                 yield $interface;
             }
         }
-
-        $parents = @class_parents($stripped);
-
-        if ($parents !== false) {
-            foreach ($parents as $parent) {
-                yield $parent;
-            }
-        }
     }
 
     /**
diff --git a/tests/Routing/RoutingSortedMiddlewareTest.php b/tests/Routing/RoutingSortedMiddlewareTest.php
index 4416f9be3686..e5877a844ce7 100644
--- a/tests/Routing/RoutingSortedMiddlewareTest.php
+++ b/tests/Routing/RoutingSortedMiddlewareTest.php
@@ -64,59 +64,4 @@ public function testItDoesNotMoveNonStringValues()
         $this->assertEquals(['a', $closure, 'b', $closure2, 'foo'], (new SortedMiddleware(['a', 'b'], ['a', $closure, 'b', $closure2, 'foo']))->all());
         $this->assertEquals([$closure, $closure2, 'foo', 'a'], (new SortedMiddleware(['a', 'b'], [$closure, $closure2, 'foo', 'a']))->all());
     }
-
-    public function testItSortsUsingParentsAndContracts()
-    {
-        $priority = [
-            FirstContractStub::class,
-            SecondStub::class,
-            'Third',
-        ];
-
-        $middleware = [
-            'Something',
-            'Something',
-            'Something',
-            'Something',
-            SecondChildStub::class,
-            'Otherthing',
-            FirstStub::class.':api',
-            'Third:foo',
-            FirstStub::class.':foo,bar',
-            'Third',
-            SecondChildStub::class,
-        ];
-
-        $expected = [
-            'Something',
-            FirstStub::class.':api',
-            FirstStub::class.':foo,bar',
-            SecondChildStub::class,
-            'Otherthing',
-            'Third:foo',
-            'Third',
-        ];
-
-        $this->assertEquals($expected, (new SortedMiddleware($priority, $middleware))->all());
-    }
-}
-
-interface FirstContractStub
-{
-    //
-}
-
-class FirstStub implements FirstContractStub
-{
-    //
-}
-
-class SecondStub
-{
-    //
-}
-
-class SecondChildStub extends SecondStub
-{
-    //
 }