diff --git a/ext/tag_list/main.php b/ext/tag_list/main.php
index 172c5c3f..c90fe8cb 100644
--- a/ext/tag_list/main.php
+++ b/ext/tag_list/main.php
@@ -334,6 +334,7 @@ class TagList extends Extension
         */
         mb_internal_encoding('UTF-8');
 
+        $tag_category_dict = [];
         if (class_exists('Shimmie2\TagCategories')) {
             $this->tagcategories = new TagCategories();
             $tag_category_dict = $this->tagcategories->getKeyedDict();