diff --git a/src/wp-content/themes/twentyseventeen/inc/customizer.php b/src/wp-content/themes/twentyseventeen/inc/customizer.php
index 4ad8cd8be4..e2566507a0 100644
--- a/src/wp-content/themes/twentyseventeen/inc/customizer.php
+++ b/src/wp-content/themes/twentyseventeen/inc/customizer.php
@@ -13,13 +13,9 @@
  * @param WP_Customize_Manager $wp_customize Theme Customizer object.
  */
 function twentyseventeen_customize_register( $wp_customize ) {
-	$postMessage_settings = array( 'blogname', 'blogdescription', 'header_textcolor' );
-	foreach( $postMessage_settings as $postMessage_setting ) {
-		$setting = $wp_customize->get_setting( $postMessage_setting );
-		if ( $setting ) {
-			$setting->transport = 'postMessage';
-		}
-	}
+	$wp_customize->get_setting( 'blogname' )->transport         = 'postMessage';
+	$wp_customize->get_setting( 'blogdescription' )->transport  = 'postMessage';
+	$wp_customize->get_setting( 'header_textcolor' )->transport = 'postMessage';
 
 	/**
 	 * Custom colors.
diff --git a/tests/phpunit/tests/customize/control.php b/tests/phpunit/tests/customize/control.php
index e6d1141219..276939327e 100644
--- a/tests/phpunit/tests/customize/control.php
+++ b/tests/phpunit/tests/customize/control.php
@@ -31,6 +31,9 @@ class Test_WP_Customize_Control extends WP_UnitTestCase {
 		$GLOBALS['wp_customize'] = new WP_Customize_Manager();
 		// @codingStandardsIgnoreEnd
 		$this->wp_customize = $GLOBALS['wp_customize'];
+
+		// Remove default theme actions that interfere with tests
+		remove_action( 'customize_register', 'twentyseventeen_customize_register' );
 	}
 
 	/**
diff --git a/tests/phpunit/tests/customize/custom-css-setting.php b/tests/phpunit/tests/customize/custom-css-setting.php
index 4c98012626..a74fe7039e 100644
--- a/tests/phpunit/tests/customize/custom-css-setting.php
+++ b/tests/phpunit/tests/customize/custom-css-setting.php
@@ -36,6 +36,9 @@ class Test_WP_Customize_Custom_CSS_Setting extends WP_UnitTestCase {
 		$this->wp_customize = new WP_Customize_Manager();
 		$wp_customize = $this->wp_customize;
 
+		// Remove default theme actions that interfere with tests
+		remove_action( 'customize_register', 'twentyseventeen_customize_register' );
+
 		do_action( 'customize_register', $this->wp_customize );
 		$this->setting = new WP_Customize_Custom_CSS_Setting( $this->wp_customize, 'custom_css[twentysixteen]' );
 		$this->wp_customize->add_setting( $this->setting );
diff --git a/tests/phpunit/tests/customize/manager.php b/tests/phpunit/tests/customize/manager.php
index 3016c70f0b..d050285ff3 100644
--- a/tests/phpunit/tests/customize/manager.php
+++ b/tests/phpunit/tests/customize/manager.php
@@ -58,6 +58,9 @@ class Tests_WP_Customize_Manager extends WP_UnitTestCase {
 		require_once( ABSPATH . WPINC . '/class-wp-customize-manager.php' );
 		$this->manager = $this->instantiate();
 		$this->undefined = new stdClass();
+
+		// Remove default theme actions that interfere with tests
+		remove_action( 'customize_register', 'twentyseventeen_customize_register' );
 	}
 
 	/**
diff --git a/tests/phpunit/tests/customize/nav-menu-item-setting.php b/tests/phpunit/tests/customize/nav-menu-item-setting.php
index ebb9748fa3..66723ad3fe 100644
--- a/tests/phpunit/tests/customize/nav-menu-item-setting.php
+++ b/tests/phpunit/tests/customize/nav-menu-item-setting.php
@@ -26,6 +26,9 @@ class Test_WP_Customize_Nav_Menu_Item_Setting extends WP_UnitTestCase {
 		global $wp_customize;
 		$this->wp_customize = new WP_Customize_Manager();
 		$wp_customize = $this->wp_customize;
+
+		// Remove default theme actions that interfere with tests
+		remove_action( 'customize_register', 'twentyseventeen_customize_register' );
 	}
 
 	/**
diff --git a/tests/phpunit/tests/customize/nav-menu-setting.php b/tests/phpunit/tests/customize/nav-menu-setting.php
index 81e3e74960..ff2c4cb63d 100644
--- a/tests/phpunit/tests/customize/nav-menu-setting.php
+++ b/tests/phpunit/tests/customize/nav-menu-setting.php
@@ -27,6 +27,9 @@ class Test_WP_Customize_Nav_Menu_Setting extends WP_UnitTestCase {
 		global $wp_customize;
 		$this->wp_customize = new WP_Customize_Manager();
 		$wp_customize = $this->wp_customize;
+
+		// Remove default theme actions that interfere with tests
+		remove_action( 'customize_register', 'twentyseventeen_customize_register' );
 	}
 
 	/**
diff --git a/tests/phpunit/tests/customize/nav-menus.php b/tests/phpunit/tests/customize/nav-menus.php
index 06e2333be3..3fbe6f0b82 100644
--- a/tests/phpunit/tests/customize/nav-menus.php
+++ b/tests/phpunit/tests/customize/nav-menus.php
@@ -26,6 +26,9 @@ class Test_WP_Customize_Nav_Menus extends WP_UnitTestCase {
 		global $wp_customize;
 		$this->wp_customize = new WP_Customize_Manager();
 		$wp_customize = $this->wp_customize;
+
+		// Remove default theme actions that interfere with tests
+		remove_action( 'customize_register', 'twentyseventeen_customize_register' );
 	}
 
 	/**
diff --git a/tests/phpunit/tests/customize/partial.php b/tests/phpunit/tests/customize/partial.php
index 944cb4e2b7..57f3c59dc0 100644
--- a/tests/phpunit/tests/customize/partial.php
+++ b/tests/phpunit/tests/customize/partial.php
@@ -39,6 +39,9 @@ class Test_WP_Customize_Partial extends WP_UnitTestCase {
 		if ( isset( $this->wp_customize->selective_refresh ) ) {
 			$this->selective_refresh = $this->wp_customize->selective_refresh;
 		}
+
+		// Remove default theme actions that interfere with tests
+		remove_action( 'customize_register', 'twentyseventeen_customize_register' );
 	}
 
 	/**
diff --git a/tests/phpunit/tests/customize/selective-refresh.php b/tests/phpunit/tests/customize/selective-refresh.php
index 73e7dc36eb..d5557dd9a8 100644
--- a/tests/phpunit/tests/customize/selective-refresh.php
+++ b/tests/phpunit/tests/customize/selective-refresh.php
@@ -39,6 +39,9 @@ class Test_WP_Customize_Selective_Refresh extends WP_UnitTestCase {
 		if ( isset( $this->wp_customize->selective_refresh ) ) {
 			$this->selective_refresh = $this->wp_customize->selective_refresh;
 		}
+
+		// Remove default theme actions that interfere with tests
+		remove_action( 'customize_register', 'twentyseventeen_customize_register' );
 	}
 
 	/**
diff --git a/tests/phpunit/tests/customize/widgets.php b/tests/phpunit/tests/customize/widgets.php
index 310320b18c..7d395c558e 100644
--- a/tests/phpunit/tests/customize/widgets.php
+++ b/tests/phpunit/tests/customize/widgets.php
@@ -45,6 +45,7 @@ class Tests_WP_Customize_Widgets extends WP_UnitTestCase {
 		remove_action( 'after_setup_theme', 'twentysixteen_setup' );
 		remove_action( 'customize_register', 'twentysixteen_customize_register', 11 );
 		remove_action( 'after_setup_theme', 'twentyseventeen_setup' );
+		remove_action( 'customize_register', 'twentyseventeen_customize_register' );
 
 		$this->backup_registered_sidebars = $GLOBALS['wp_registered_sidebars'];