diff --git a/tests/phpunit/tests/ThemesScreens/ThemesScreens_ConstructTest.php b/tests/phpunit/tests/ThemesScreens/ThemesScreens_ConstructTest.php
new file mode 100644
index 0000000..fb3b8b6
--- /dev/null
+++ b/tests/phpunit/tests/ThemesScreens/ThemesScreens_ConstructTest.php
@@ -0,0 +1,68 @@
+<?php
+/**
+ * Class ThemesScreens_ConstructTest
+ *
+ * @package AspireUpdate
+ */
+
+/**
+ * Tests for Themes_Screens::__construct()
+ *
+ * These tests cause constants to be defined.
+ * They must run in separate processes and must not preserve global state.
+ *
+ * @runTestsInSeparateProcesses
+ * @preserveGlobalState disabled
+ *
+ * @covers \AspireUpdate\Themes_Screens::__construct
+ *
+ */
+class ThemesScreens_ConstructTest extends WP_UnitTestCase {
+	/**
+	 * Test that hooks are added when API rewriting is enabled.
+	 *
+	 * @dataProvider data_hooks_and_methods
+	 *
+	 * @string $hook   The hook's name.
+	 * @string $method The method to hook.
+	 */
+	public function test_should_add_hooks( $hook, $method ) {
+		define( 'AP_ENABLE', true );
+
+		$themes_screens = new AspireUpdate\Themes_Screens();
+		$this->assertIsInt( has_action( $hook, [ $themes_screens, $method ] ) );
+	}
+
+	/**
+	 * Test that hooks are not added when API rewriting is disabled.
+	 *
+	 * @dataProvider data_hooks_and_methods
+	 *
+	 * @string $hook   The hook's name.
+	 * @string $method The method to hook.
+	 */
+	public function test_should_not_add_hooks( $hook, $method ) {
+		define( 'AP_ENABLE', false );
+
+		$themes_screens = new AspireUpdate\Themes_Screens();
+		$this->assertFalse( has_action( $hook, [ $themes_screens, $method ] ) );
+	}
+
+	/**
+	 * Data provider.
+	 *
+	 * @return array[]
+	 */
+	public function data_hooks_and_methods() {
+		return [
+			'admin_enqueue_scripts -> admin_enqueue_scripts' => [
+				'hook'   => 'admin_enqueue_scripts',
+				'method' => 'admin_enqueue_scripts',
+			],
+			'load-theme-install.php -> redirect_to_theme_install' => [
+				'hook'   => 'load-theme-install.php',
+				'method' => 'redirect_to_theme_install',
+			],
+		];
+	}
+}