diff --git a/src/game/WorldHandlers/GridMap.h b/src/game/WorldHandlers/GridMap.h
index c501f9a8..5b5410af 100644
--- a/src/game/WorldHandlers/GridMap.h
+++ b/src/game/WorldHandlers/GridMap.h
@@ -286,7 +286,7 @@ class TerrainInfo : public Referencable<AtomicLong>
 };
 
 // class for managing TerrainData object and all sort of geometry querying operations
-class TerrainManager : public MaNGOS::Singleton<TerrainManager>, MaNGOS::ClassLevelLockable<TerrainManager, ACE_Thread_Mutex>
+class TerrainManager : public MaNGOS::Singleton<TerrainManager, MaNGOS::ClassLevelLockable<TerrainManager, ACE_Thread_Mutex> >
 {
         typedef UNORDERED_MAP<uint32,  TerrainInfo*> TerrainDataMap;
         friend class MaNGOS::OperatorNew<TerrainManager>;