diff --git a/lib/class-importer.php b/lib/class-importer.php
index b83e597..88bbf02 100644
--- a/lib/class-importer.php
+++ b/lib/class-importer.php
@@ -194,6 +194,7 @@ public function import( array $data, $skip_sleep = false, $import_ignored_functi
 		 */
 		delete_option( "{$this->taxonomy_package}_children" );
 		delete_option( "{$this->taxonomy_since_version}_children" );
+		delete_option( "{$this->taxonomy_namespace}_children" );
 
 		/**
 		 * Action at the end of a complete import