diff --git a/inc/gtm/namespace.php b/inc/gtm/namespace.php
index 54f87d4..4fd9a56 100644
--- a/inc/gtm/namespace.php
+++ b/inc/gtm/namespace.php
@@ -13,7 +13,8 @@
  * Kick it off.
  */
 function bootstrap() {
-	$gtm = Altis\get_config()['modules']['analytics']['google-tag-manager'];
+	$config = Altis\get_config();
+	$gtm = $config['modules']['analytics']['google-tag-manager'] ?? '';
 
 	// Bail if we aren't using GTM.
 	if ( empty( $gtm ) ) {