diff --git a/src/wp-includes/class-wp-theme.php b/src/wp-includes/class-wp-theme.php
index f4c2e1b710..3e6c62906b 100644
--- a/src/wp-includes/class-wp-theme.php
+++ b/src/wp-includes/class-wp-theme.php
@@ -252,7 +252,7 @@ final class WP_Theme implements ArrayAccess {
 
 		if ( ! $this->template && $this->stylesheet === $this->headers['Template'] ) {
 			/* translators: %s: Template */
-			$this->errors = new WP_Error( 'theme_child_invalid', sprintf( __( 'The theme defines itself as its parent theme. Please check the "%s" header.' ), 'Template' ) );
+			$this->errors = new WP_Error( 'theme_child_invalid', sprintf( __( 'The theme defines itself as its parent theme. Please check the %s header.' ), '<code>Template</code>' ) );
 			$this->cache_add( 'theme', array( 'headers' => $this->headers, 'errors' => $this->errors, 'stylesheet' => $this->stylesheet ) );
 
 			return;