diff --git a/webapp/controller/HeroController.class.php b/webapp/controller/HeroController.class.php
index 982c24a4..a2b7c31d 100644
--- a/webapp/controller/HeroController.class.php
+++ b/webapp/controller/HeroController.class.php
@@ -226,7 +226,7 @@ class HeroController extends BaseAuthedController {
                 $nextQualityMeta = mt\HeroQuality::getByQuality($heroDb['quality'] + 1);
                 if ($nextQualityMeta) {
                     $rnd = rand(1, 100);
-                    if ($rand > $nextQualityMeta['success_rate']) {
+                    if ($rnd > $nextQualityMeta['success_rate']) {
                         Hero::update($heroUniId,
                                      array(
                                          'advanced_count' => $heroDb['advanced_count'] + 1,