diff --git a/classes/Thumbnail.php b/classes/Thumbnail.php
index 308a0e75e70a99cbcdb0b97ca3d345d5495abf37..e61f63d2118fed69b8b919741706e77ae9d34247 100644
--- a/classes/Thumbnail.php
+++ b/classes/Thumbnail.php
@@ -36,7 +36,7 @@ class Thumbnail
 
     public static function gc()
     {
-        if (mt_rand(0, 100) >= 98) {
+        if (mt_rand(0, 100) < 98) {
             return;
         }