diff --git a/tests/phpunit/tests/sitemaps/functions.php b/tests/phpunit/tests/sitemaps/functions.php
index a4913fae5f..45eb96b4af 100644
--- a/tests/phpunit/tests/sitemaps/functions.php
+++ b/tests/phpunit/tests/sitemaps/functions.php
@@ -3,7 +3,8 @@
 /**
  * @group sitemaps
  */
-class Test_Sitemaps_Functions extends WP_UnitTestCase {
+class Tests_Sitemaps_Functions extends WP_UnitTestCase {
+
 	/**
 	 * Test getting the correct number of URLs for a sitemap.
 	 */
@@ -60,11 +61,11 @@ class Test_Sitemaps_Functions extends WP_UnitTestCase {
 	}
 
 	/**
-	 * Test get_sitemap_url() with ugly permalinks.
+	 * Test get_sitemap_url() with plain permalinks.
 	 *
-	 * @dataProvider ugly_permalinks_provider
+	 * @dataProvider plain_permalinks_provider
 	 */
-	public function test_get_sitemap_url_ugly_permalinks( $name, $subtype_name, $page, $expected ) {
+	public function test_get_sitemap_url_plain_permalinks( $name, $subtype_name, $page, $expected ) {
 		$actual = get_sitemap_url( $name, $subtype_name, $page );
 
 		$this->assertSame( $expected, $actual );
@@ -84,7 +85,7 @@ class Test_Sitemaps_Functions extends WP_UnitTestCase {
 	}
 
 	/**
-	 * Data provider for test_get_sitemap_url_ugly_permalinks.
+	 * Data provider for test_get_sitemap_url_plain_permalinks.
 	 *
 	 * @return array[] {
 	 *     Data to test with.
@@ -95,7 +96,7 @@ class Test_Sitemaps_Functions extends WP_UnitTestCase {
 	 *     @type string|false $4 Sitemap URL.
 	 * }
 	 */
-	function ugly_permalinks_provider() {
+	function plain_permalinks_provider() {
 		return array(
 			array( 'posts', 'post', 1, home_url( '/?sitemap=posts&sitemap-subtype=post&paged=1' ) ),
 			array( 'posts', 'post', 0, home_url( '/?sitemap=posts&sitemap-subtype=post&paged=1' ) ),
diff --git a/tests/phpunit/tests/sitemaps/sitemaps.php b/tests/phpunit/tests/sitemaps/sitemaps.php
index 6cbe77b008..a4fa6b14d7 100644
--- a/tests/phpunit/tests/sitemaps/sitemaps.php
+++ b/tests/phpunit/tests/sitemaps/sitemaps.php
@@ -1,6 +1,6 @@
 <?php
 /**
- * Sitemaps: Sitemaps_Tests class
+ * Sitemaps: Tests_Sitemaps_Sitemaps class
  *
  * Main test class.
  *
@@ -15,7 +15,7 @@
  *
  * @group sitemaps
  */
-class Test_Sitemaps extends WP_UnitTestCase {
+class Tests_Sitemaps_Sitemaps extends WP_UnitTestCase {
 
 	/**
 	 * List of user IDs.
diff --git a/tests/phpunit/tests/sitemaps/sitemaps-index.php b/tests/phpunit/tests/sitemaps/wpSitemapsIndex.php
similarity index 97%
rename from tests/phpunit/tests/sitemaps/sitemaps-index.php
rename to tests/phpunit/tests/sitemaps/wpSitemapsIndex.php
index f959da8344..44d6df40f6 100644
--- a/tests/phpunit/tests/sitemaps/sitemaps-index.php
+++ b/tests/phpunit/tests/sitemaps/wpSitemapsIndex.php
@@ -3,7 +3,8 @@
 /**
  * @group sitemaps
  */
-class Test_WP_Sitemaps_Index extends WP_UnitTestCase {
+class Tests_Sitemaps_wpSitemapsIndex extends WP_UnitTestCase {
+
 	public function test_get_sitemap_list() {
 		$registry = new WP_Sitemaps_Registry();
 
diff --git a/tests/phpunit/tests/sitemaps/sitemaps-posts.php b/tests/phpunit/tests/sitemaps/wpSitemapsPosts.php
similarity index 96%
rename from tests/phpunit/tests/sitemaps/sitemaps-posts.php
rename to tests/phpunit/tests/sitemaps/wpSitemapsPosts.php
index 169729a28b..b60903e18a 100644
--- a/tests/phpunit/tests/sitemaps/sitemaps-posts.php
+++ b/tests/phpunit/tests/sitemaps/wpSitemapsPosts.php
@@ -3,7 +3,8 @@
 /**
  * @group sitemaps
  */
-class Test_WP_Sitemaps_Posts extends WP_UnitTestCase {
+class Tests_Sitemaps_wpSitemapsPosts extends WP_UnitTestCase {
+
 	/**
 	 * Tests getting sitemap entries for post type page with 'posts' homepage.
 	 *
diff --git a/tests/phpunit/tests/sitemaps/sitemaps-registry.php b/tests/phpunit/tests/sitemaps/wpSitemapsRegistry.php
similarity index 93%
rename from tests/phpunit/tests/sitemaps/sitemaps-registry.php
rename to tests/phpunit/tests/sitemaps/wpSitemapsRegistry.php
index b5ac7e952c..8032a38dcc 100644
--- a/tests/phpunit/tests/sitemaps/sitemaps-registry.php
+++ b/tests/phpunit/tests/sitemaps/wpSitemapsRegistry.php
@@ -3,7 +3,8 @@
 /**
  * @group sitemaps
  */
-class Test_WP_Sitemaps_Registry extends WP_UnitTestCase {
+class Tests_Sitemaps_wpSitemapsRegistry extends WP_UnitTestCase {
+
 	public function test_add_provider() {
 		$provider = new WP_Sitemaps_Test_Provider();
 		$registry = new WP_Sitemaps_Registry();
diff --git a/tests/phpunit/tests/sitemaps/sitemaps-renderer.php b/tests/phpunit/tests/sitemaps/wpSitemapsRenderer.php
similarity index 99%
rename from tests/phpunit/tests/sitemaps/sitemaps-renderer.php
rename to tests/phpunit/tests/sitemaps/wpSitemapsRenderer.php
index f2ee1de1c7..8ab5e5e3ba 100644
--- a/tests/phpunit/tests/sitemaps/sitemaps-renderer.php
+++ b/tests/phpunit/tests/sitemaps/wpSitemapsRenderer.php
@@ -3,7 +3,8 @@
 /**
  * @group sitemaps
  */
-class Test_WP_Sitemaps_Renderer extends WP_Test_XML_TestCase {
+class Tests_Sitemaps_wpSitemapsRenderer extends WP_Test_XML_TestCase {
+
 	public function test_get_sitemap_stylesheet_url() {
 		$sitemap_renderer = new WP_Sitemaps_Renderer();
 		$stylesheet_url   = $sitemap_renderer->get_sitemap_stylesheet_url();
diff --git a/tests/phpunit/tests/sitemaps/sitemaps-stylesheet.php b/tests/phpunit/tests/sitemaps/wpSitemapsStylesheet.php
similarity index 94%
rename from tests/phpunit/tests/sitemaps/sitemaps-stylesheet.php
rename to tests/phpunit/tests/sitemaps/wpSitemapsStylesheet.php
index 09aacf0440..b4dab08e48 100644
--- a/tests/phpunit/tests/sitemaps/sitemaps-stylesheet.php
+++ b/tests/phpunit/tests/sitemaps/wpSitemapsStylesheet.php
@@ -3,7 +3,8 @@
 /**
  * @group sitemaps
  */
-class Test_WP_Sitemaps_Stylesheet extends WP_UnitTestCase {
+class Tests_Sitemaps_wpSitemapsStylesheet extends WP_UnitTestCase {
+
 	/**
 	 * Test that stylesheet content can be filtered.
 	 */
diff --git a/tests/phpunit/tests/sitemaps/sitemaps-taxonomies.php b/tests/phpunit/tests/sitemaps/wpSitemapsTaxonomies.php
similarity index 99%
rename from tests/phpunit/tests/sitemaps/sitemaps-taxonomies.php
rename to tests/phpunit/tests/sitemaps/wpSitemapsTaxonomies.php
index e98c6b71ee..456efe06e9 100644
--- a/tests/phpunit/tests/sitemaps/sitemaps-taxonomies.php
+++ b/tests/phpunit/tests/sitemaps/wpSitemapsTaxonomies.php
@@ -3,7 +3,8 @@
 /**
  * @group sitemaps
  */
-class Test_WP_Sitemaps_Taxonomies extends WP_UnitTestCase {
+class Tests_Sitemaps_wpSitemapsTaxonomies extends WP_UnitTestCase {
+
 	/**
 	 * List of post_tag IDs.
 	 *
diff --git a/tests/phpunit/tests/sitemaps/sitemaps-users.php b/tests/phpunit/tests/sitemaps/wpSitemapsUsers.php
similarity index 95%
rename from tests/phpunit/tests/sitemaps/sitemaps-users.php
rename to tests/phpunit/tests/sitemaps/wpSitemapsUsers.php
index 3cd76d3376..d52e191835 100644
--- a/tests/phpunit/tests/sitemaps/sitemaps-users.php
+++ b/tests/phpunit/tests/sitemaps/wpSitemapsUsers.php
@@ -3,7 +3,8 @@
 /**
  * @group sitemaps
  */
-class Test_WP_Sitemaps_Users extends WP_UnitTestCase {
+class Tests_Sitemaps_wpSitemapsUsers extends WP_UnitTestCase {
+
 	/**
 	 * List of user IDs.
 	 *