diff --git a/src/Utility/Migrations/2024_08_20_163744_add_indexes_for_url_tracing.php b/src/Utility/Migrations/2024_08_20_163744_add_indexes_for_url_tracing.php
index cbeb956..2754e24 100644
--- a/src/Utility/Migrations/2024_08_20_163744_add_indexes_for_url_tracing.php
+++ b/src/Utility/Migrations/2024_08_20_163744_add_indexes_for_url_tracing.php
@@ -14,7 +14,7 @@
     public function up()
     {
         Schema::table('short_url_tracings', function (Blueprint $table) {
-            $table->index(['utm_source', 'utm_medium', 'utm_campaign', 'utm_content', 'utm_term'], 'utm_composite_index');
+            $table->index(['utm_source(100)', 'utm_medium(100)', 'utm_campaign(100)', 'utm_content(100)', 'utm_term(100)'], 'utm_composite_index');
         });
     }
 };