diff --git a/tests/phpunit/tests/rewrite/oldSlugRedirect.php b/tests/phpunit/tests/rewrite/oldSlugRedirect.php
index 754ad996ff..cf38ba452e 100644
--- a/tests/phpunit/tests/rewrite/oldSlugRedirect.php
+++ b/tests/phpunit/tests/rewrite/oldSlugRedirect.php
@@ -8,17 +8,19 @@
 class Tests_Rewrite_OldSlugRedirect extends WP_UnitTestCase {
 	protected $old_slug_redirect_url;
 
-	protected $post_id;
+	protected static $post_id;
 
-	public function set_up() {
-		parent::set_up();
-
-		$this->post_id = self::factory()->post->create(
+	public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
+		self::$post_id = $factory->post->create(
 			array(
 				'post_title' => 'Foo Bar',
 				'post_name'  => 'foo-bar',
 			)
 		);
+	}
+
+	public function set_up() {
+		parent::set_up();
 
 		add_filter( 'old_slug_redirect_url', array( $this, 'filter_old_slug_redirect_url' ), 10, 1 );
 
@@ -37,16 +39,16 @@ class Tests_Rewrite_OldSlugRedirect extends WP_UnitTestCase {
 	}
 
 	public function test_old_slug_redirect() {
-		$old_permalink = user_trailingslashit( get_permalink( $this->post_id ) );
+		$old_permalink = user_trailingslashit( get_permalink( self::$post_id ) );
 
 		wp_update_post(
 			array(
-				'ID'        => $this->post_id,
+				'ID'        => self::$post_id,
 				'post_name' => 'bar-baz',
 			)
 		);
 
-		$permalink = user_trailingslashit( get_permalink( $this->post_id ) );
+		$permalink = user_trailingslashit( get_permalink( self::$post_id ) );
 
 		$this->go_to( $old_permalink );
 		wp_old_slug_redirect();
@@ -57,16 +59,16 @@ class Tests_Rewrite_OldSlugRedirect extends WP_UnitTestCase {
 	 * @ticket 36723
 	 */
 	public function test_old_slug_redirect_cache() {
-		$old_permalink = user_trailingslashit( get_permalink( $this->post_id ) );
+		$old_permalink = user_trailingslashit( get_permalink( self::$post_id ) );
 
 		wp_update_post(
 			array(
-				'ID'        => $this->post_id,
+				'ID'        => self::$post_id,
 				'post_name' => 'bar-baz',
 			)
 		);
 
-		$permalink = user_trailingslashit( get_permalink( $this->post_id ) );
+		$permalink = user_trailingslashit( get_permalink( self::$post_id ) );
 
 		$this->go_to( $old_permalink );
 
@@ -83,16 +85,16 @@ class Tests_Rewrite_OldSlugRedirect extends WP_UnitTestCase {
 	 * @ticket 36723
 	 */
 	public function test_old_slug_redirect_cache_invalidation() {
-		$old_permalink = user_trailingslashit( get_permalink( $this->post_id ) );
+		$old_permalink = user_trailingslashit( get_permalink( self::$post_id ) );
 
 		wp_update_post(
 			array(
-				'ID'        => $this->post_id,
+				'ID'        => self::$post_id,
 				'post_name' => 'bar-baz',
 			)
 		);
 
-		$permalink = user_trailingslashit( get_permalink( $this->post_id ) );
+		$permalink = user_trailingslashit( get_permalink( self::$post_id ) );
 
 		$this->go_to( $old_permalink );
 
@@ -101,12 +103,12 @@ class Tests_Rewrite_OldSlugRedirect extends WP_UnitTestCase {
 
 		wp_update_post(
 			array(
-				'ID'        => $this->post_id,
+				'ID'        => self::$post_id,
 				'post_name' => 'foo-bar-baz',
 			)
 		);
 
-		$permalink = user_trailingslashit( get_permalink( $this->post_id ) );
+		$permalink = user_trailingslashit( get_permalink( self::$post_id ) );
 
 		$num_queries = get_num_queries();
 		wp_old_slug_redirect();
@@ -118,7 +120,7 @@ class Tests_Rewrite_OldSlugRedirect extends WP_UnitTestCase {
 		$file          = DIR_TESTDATA . '/images/canola.jpg';
 		$attachment_id = self::factory()->attachment->create_object(
 			$file,
-			$this->post_id,
+			self::$post_id,
 			array(
 				'post_mime_type' => 'image/jpeg',
 				'post_name'      => 'my-attachment',
@@ -129,7 +131,7 @@ class Tests_Rewrite_OldSlugRedirect extends WP_UnitTestCase {
 
 		wp_update_post(
 			array(
-				'ID'        => $this->post_id,
+				'ID'        => self::$post_id,
 				'post_name' => 'bar-baz',
 			)
 		);
@@ -148,7 +150,7 @@ class Tests_Rewrite_OldSlugRedirect extends WP_UnitTestCase {
 			)
 		);
 
-		$permalink = user_trailingslashit( trailingslashit( get_permalink( $this->post_id ) ) . 'the-attachment' );
+		$permalink = user_trailingslashit( trailingslashit( get_permalink( self::$post_id ) ) . 'the-attachment' );
 
 		$this->go_to( $old_permalink );
 		wp_old_slug_redirect();
@@ -158,21 +160,21 @@ class Tests_Rewrite_OldSlugRedirect extends WP_UnitTestCase {
 	public function test_old_slug_redirect_paged() {
 		wp_update_post(
 			array(
-				'ID'           => $this->post_id,
+				'ID'           => self::$post_id,
 				'post_content' => 'Test<!--nextpage-->Test',
 			)
 		);
 
-		$old_permalink = user_trailingslashit( trailingslashit( get_permalink( $this->post_id ) ) . 'page/2' );
+		$old_permalink = user_trailingslashit( trailingslashit( get_permalink( self::$post_id ) ) . 'page/2' );
 
 		wp_update_post(
 			array(
-				'ID'        => $this->post_id,
+				'ID'        => self::$post_id,
 				'post_name' => 'bar-baz',
 			)
 		);
 
-		$permalink = user_trailingslashit( trailingslashit( get_permalink( $this->post_id ) ) . 'page/2' );
+		$permalink = user_trailingslashit( trailingslashit( get_permalink( self::$post_id ) ) . 'page/2' );
 
 		$this->go_to( $old_permalink );
 		wp_old_slug_redirect();
@@ -183,11 +185,11 @@ class Tests_Rewrite_OldSlugRedirect extends WP_UnitTestCase {
 	 * @ticket 35031
 	 */
 	public function test_old_slug_doesnt_redirect_when_reused() {
-		$old_permalink = user_trailingslashit( get_permalink( $this->post_id ) );
+		$old_permalink = user_trailingslashit( get_permalink( self::$post_id ) );
 
 		wp_update_post(
 			array(
-				'ID'        => $this->post_id,
+				'ID'        => self::$post_id,
 				'post_name' => 'bar-baz',
 			)
 		);