diff --git a/src/server/scripts/Northrend/Naxxramas/instance_naxxramas.cpp b/src/server/scripts/Northrend/Naxxramas/instance_naxxramas.cpp
index bfb88be6ea..3a032ade7a 100644
--- a/src/server/scripts/Northrend/Naxxramas/instance_naxxramas.cpp
+++ b/src/server/scripts/Northrend/Naxxramas/instance_naxxramas.cpp
@@ -595,6 +595,7 @@ public:
                     case NOT_STARTED:
                     {
                         _horsemanAchievement = true;
+                        _events.CancelEvent(EVENT_AND_THEY_WOULD_ALL_GO_DOWN_TOGETHER);
 
                         if (!horsemanKilled)
                             break;