diff --git a/tests/phpunit/tests/taxonomy.php b/tests/phpunit/tests/taxonomy.php
index 21b9977a85366..e81f38f53dbcc 100644
--- a/tests/phpunit/tests/taxonomy.php
+++ b/tests/phpunit/tests/taxonomy.php
@@ -16,6 +16,30 @@ public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
 		self::$editor_id = $factory->user->create( array( 'role' => 'editor' ) );
 	}
 
+	/**
+	 * Tear down after each test.
+	 */
+	public function tear_down() {
+		unregister_taxonomy( 'wptests_tax' );
+		unregister_taxonomy( 'wptests_tax_1' );
+		unregister_taxonomy( 'wptests_tax_2' );
+		unregister_taxonomy( 'wptests_conflict' );
+		unregister_taxonomy( 'taxonomy53212' );
+		unregister_taxonomy( 'random' );
+		unregister_taxonomy( 'foo' );
+		unregister_taxonomy( 'tax_new' );
+		unregister_taxonomy( 'test_tax' );
+		unregister_taxonomy( 'custom-tax' );
+		unregister_taxonomy( 'test_tax1' );
+		unregister_taxonomy( 'test_tax2' );
+		unregister_post_type( 'test_cpt' );
+		unregister_post_type( 'wptests_pt' );
+		unregister_post_type( 'wptests_conflict' );
+		unregister_post_type( 'post-custom-tax' );
+		unregister_post_type( 'test_post_type' );
+		parent::tear_down();
+	}
+
 	public function test_get_post_taxonomies() {
 		$this->assertSame( array( 'category', 'post_tag', 'post_format' ), get_object_taxonomies( 'post' ) );
 	}
@@ -212,7 +236,7 @@ public function test_register_taxonomy() {
 		$this->assertFalse( is_taxonomy_hierarchical( $tax ) );
 
 		// Clean up.
-		unset( $GLOBALS['wp_taxonomies'][ $tax ] );
+		unregister_taxonomy( $tax );
 	}
 
 	public function test_register_hierarchical_taxonomy() {
@@ -226,7 +250,7 @@ public function test_register_hierarchical_taxonomy() {
 		$this->assertTrue( is_taxonomy_hierarchical( $tax ) );
 
 		// Clean up.
-		unset( $GLOBALS['wp_taxonomies'][ $tax ] );
+		unregister_taxonomy( $tax );
 	}
 
 	/**
@@ -341,7 +365,7 @@ public function test_registering_taxonomies_to_object_types() {
 		$this->assertFalse( register_taxonomy_for_object_type( $tax, 'user' ) );
 		$this->assertFalse( unregister_taxonomy_for_object_type( $tax, 'user' ) );
 
-		unset( $GLOBALS['wp_taxonomies'][ $tax ] );
+		unregister_taxonomy( $tax );
 		_unregister_post_type( $post_type );
 	}
 
@@ -646,7 +670,6 @@ public function test_get_ancestors_taxonomy_post_type_conflict_resource_type_tax
 		$this->assertSameSets( array( $p1 ), get_ancestors( $p2, 'wptests_conflict', 'post_type' ) );
 		$this->assertSameSets( array( $t1 ), get_ancestors( $t2, 'wptests_conflict', 'taxonomy' ) );
 		$this->assertSameSets( array( $t1 ), get_ancestors( $t2, 'wptests_conflict' ) );
-		_unregister_post_type( 'wptests_pt' );
 	}
 
 	/**