diff --git a/src/server/game/Pools/PoolMgr.h b/src/server/game/Pools/PoolMgr.h
index 0884ec1c4e9..e1cea9d7f89 100644
--- a/src/server/game/Pools/PoolMgr.h
+++ b/src/server/game/Pools/PoolMgr.h
@@ -22,6 +22,7 @@
 #include "Define.h"
 #include <map>
 #include <set>
+#include <unordered_map>
 #include <vector>
 
 class Creature;