diff --git a/server/gameserver/hero.cc b/server/gameserver/hero.cc
index 74d245b..5627097 100644
--- a/server/gameserver/hero.cc
+++ b/server/gameserver/hero.cc
@@ -320,7 +320,7 @@ void Hero::InitAI()
         }
     }
     if (ai_meta->i->ai_kind() == kAI_MineSweeper) {
-        int time = 500 + rand() % 1500;
+        int time = 500 + rand() % 500;
         int idle_time = 300 + rand() % 300;
         ((HeroAI*)ai)->ForceRandomWalk(time, idle_time);
     }