diff --git a/index.php b/index.php
index f510b5d..2440b1c 100644
--- a/index.php
+++ b/index.php
@@ -1,10 +1,10 @@
 <?php
 $block_slug = basename( dirname( __FILE__ ) );
-
-$theme_slug = get_option( 'stylesheet' );
+// TODO calculate this correctly whether this file is within a theme or plugin
+$block_namespace = get_option( 'stylesheet' );
 
 add_action( 'init', function() {
-	global $block_slug, $theme_slug;
+	global $block_slug, $block_namespace;
 
 	if ( ! function_exists( 'register_block_type' ) ) {
 		return;
@@ -39,7 +39,7 @@ add_action( 'init', function() {
 		filemtime( "$dir/$style_css" )
 	);
 
-	register_block_type( "$theme_slug/$block_slug", array(
+	register_block_type( "$block_namespace/$block_slug", array(
 		'editor_script' => "{$block_slug}-block-editor",
 		'editor_style'  => "{$block_slug}-block-editor",
 		'style'         => "{$block_slug}-block",