diff --git a/src/wp-admin/custom-header.php b/src/wp-admin/custom-header.php
index 9822c9ba84..5cc64ef7bf 100644
--- a/src/wp-admin/custom-header.php
+++ b/src/wp-admin/custom-header.php
@@ -639,7 +639,7 @@ class Custom_Image_Header {
 </tr>
 	<?php endif;
 
-	$default_image = get_theme_support( 'custom-header', 'default-image' );
+	$default_image = sprintf( get_theme_support( 'custom-header', 'default-image' ), get_template_directory_uri(), get_stylesheet_directory_uri() );
 	if ( $default_image && get_header_image() != $default_image ) : ?>
 <tr>
 <th scope="row"><?php _e( 'Reset Image' ); ?></th>
diff --git a/src/wp-includes/class-wp-customize-manager.php b/src/wp-includes/class-wp-customize-manager.php
index c701364149..6e8faf2a8d 100644
--- a/src/wp-includes/class-wp-customize-manager.php
+++ b/src/wp-includes/class-wp-customize-manager.php
@@ -3439,12 +3439,11 @@ final class WP_Customize_Manager {
 		) );
 
 		$this->add_setting( new WP_Customize_Filter_Setting( $this, 'header_image', array(
-			'default'        => get_theme_support( 'custom-header', 'default-image' ),
+			'default'        => sprintf( get_theme_support( 'custom-header', 'default-image' ), get_template_directory_uri(), get_stylesheet_directory_uri() ),
 			'theme_supports' => 'custom-header',
 		) ) );
 
 		$this->add_setting( new WP_Customize_Header_Image_Setting( $this, 'header_image_data', array(
-			// 'default'        => get_theme_support( 'custom-header', 'default-image' ),
 			'theme_supports' => 'custom-header',
 		) ) );