diff --git a/wp-admin/theme-editor.php b/wp-admin/theme-editor.php
index a84aebeb31..8660f60414 100644
--- a/wp-admin/theme-editor.php
+++ b/wp-admin/theme-editor.php
@@ -51,7 +51,7 @@ else
 
 $theme = wp_get_theme( $stylesheet );
 
-if ( ! $theme )
+if ( ! $theme->exists() )
 	wp_die( __( 'The requested theme does not exist.' ) );
 
 $allowed_files = $theme->get_files( 'php', 1 );