diff --git a/tests/unit/ElpUploadHandlerTest.php b/tests/unit/ElpUploadHandlerTest.php
index cc78ec8..36e546c 100644
--- a/tests/unit/ElpUploadHandlerTest.php
+++ b/tests/unit/ElpUploadHandlerTest.php
@@ -19,6 +19,14 @@ class ElpUploadHandlerTest extends WP_UnitTestCase {
 	 */
 	private $handler;
 
+	/**
+	 * Paths removed in tear_down(), so a failing test cannot leak them into the
+	 * shared uploads directory of the next run.
+	 *
+	 * @var string[]
+	 */
+	private $cleanup_paths = array();
+
 	/**
 	 * Set up test fixtures.
 	 */
@@ -27,6 +35,17 @@ public function set_up() {
 		$this->handler = new ExeLearning_Elp_Upload_Handler();
 	}
 
+	/**
+	 * Tear down test fixtures.
+	 */
+	public function tear_down() {
+		foreach ( $this->cleanup_paths as $path ) {
+			ExeLearning_Styles_Service::recursive_delete( $path );
+		}
+		$this->cleanup_paths = array();
+		parent::tear_down();
+	}
+
 	/**
 	 * Test process_elp_upload ignores non-elpx files.
 	 */
@@ -170,6 +189,7 @@ private function create_extraction_folder() {
 
 		wp_mkdir_p( $path );
 		file_put_contents( $path . 'index.html', '<!doctype html>' ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_file_put_contents
+		$this->cleanup_paths[] = $path;
 
 		return array( $hash, $path );
 	}
@@ -196,7 +216,7 @@ public function test_delete_extracted_folder_no_metadata() {
 	public function test_delete_extracted_folder_nonexistent_dir() {
 		list( , $bystander ) = $this->create_extraction_folder();
 		$attachment_id       = $this->factory->attachment->create();
-		$missing_hash        = str_repeat( 'f', 40 );
+		$missing_hash        = sha1( uniqid( 'exe-missing-', true ) );
 
 		update_post_meta( $attachment_id, '_exelearning_extracted', $missing_hash );
 
diff --git a/tests/unit/RestApiTest.php b/tests/unit/RestApiTest.php
index 61afa14..2cd3225 100644
--- a/tests/unit/RestApiTest.php
+++ b/tests/unit/RestApiTest.php
@@ -19,6 +19,14 @@ class RestApiTest extends WP_UnitTestCase {
 	 */
 	private $rest_api;
 
+	/**
+	 * Paths removed in tear_down(), so a failing test cannot leak them into the
+	 * shared uploads directory of the next run.
+	 *
+	 * @var string[]
+	 */
+	private $cleanup_paths = array();
+
 	/**
 	 * Set up test fixtures.
 	 */
@@ -38,6 +46,10 @@ public function set_up() {
 	public function tear_down() {
 		global $wp_rest_server;
 		$wp_rest_server = null;
+		foreach ( $this->cleanup_paths as $path ) {
+			ExeLearning_Styles_Service::recursive_delete( $path );
+		}
+		$this->cleanup_paths = array();
 		parent::tear_down();
 	}
 
@@ -1361,6 +1373,8 @@ public function test_save_elp_file_cleanup_with_old_extraction() {
 		$old_folder = $upload_dir['basedir'] . '/exelearning/' . $old_hash . '/';
 		wp_mkdir_p( $old_folder );
 		file_put_contents( $old_folder . 'index.html', '<html></html>' );
+		$this->cleanup_paths[] = $old_folder;
+		$this->cleanup_paths[] = $file_path;
 
 		update_post_meta( $attachment_id, '_exelearning_extracted', $old_hash );
 
@@ -1380,14 +1394,10 @@ public function test_save_elp_file_cleanup_with_old_extraction() {
 
 		$result = $this->rest_api->save_elp_file( $request );
 
+		unset( $_FILES['file'] );
+
 		// Reprocessing fails (invalid ZIP), so old folder should be preserved.
 		$this->assertTrue( is_dir( $old_folder ) );
-
-		// Clean up test directory.
-		unlink( $old_folder . 'index.html' );
-		rmdir( $old_folder );
-		unlink( $file_path );
-		unset( $_FILES['file'] );
 	}
 
 	/**
@@ -1842,6 +1852,7 @@ public function test_cleanup_old_extraction_with_folder() {
 
 		wp_mkdir_p( $folder );
 		file_put_contents( $folder . 'test.html', '<html></html>' );
+		$this->cleanup_paths[] = $folder;
 
 		update_post_meta( $attachment_id, '_exelearning_extracted', $hash );
 
diff --git a/tests/unit/ShortcodesTest.php b/tests/unit/ShortcodesTest.php
index bb9353d..41cb8b4 100644
--- a/tests/unit/ShortcodesTest.php
+++ b/tests/unit/ShortcodesTest.php
@@ -19,6 +19,14 @@ class ShortcodesTest extends WP_UnitTestCase {
 	 */
 	private $shortcodes;
 
+	/**
+	 * Paths removed in tear_down(), so a failing test cannot leak them into the
+	 * shared uploads directory of the next run.
+	 *
+	 * @var string[]
+	 */
+	private $cleanup_paths = array();
+
 	/**
 	 * Set up test fixtures.
 	 */
@@ -27,6 +35,17 @@ public function set_up() {
 		$this->shortcodes = new ExeLearning_Shortcodes();
 	}
 
+	/**
+	 * Tear down test fixtures.
+	 */
+	public function tear_down() {
+		foreach ( $this->cleanup_paths as $path ) {
+			ExeLearning_Styles_Service::recursive_delete( $path );
+		}
+		$this->cleanup_paths = array();
+		parent::tear_down();
+	}
+
 	/**
 	 * Test shortcode is registered.
 	 */
@@ -317,6 +336,7 @@ private function create_previewable_attachment( $hash, $with_screenshot = false
 			$dir        = trailingslashit( $upload_dir['basedir'] ) . 'exelearning/' . $hash;
 			wp_mkdir_p( $dir );
 			file_put_contents( $dir . '/screenshot.png', 'PNG' ); // phpcs:ignore
+			$this->cleanup_paths[] = $dir;
 		}
 
 		return $attachment_id;