diff --git a/src/game/UnitAI.h b/src/game/UnitAI.h
index 095edb0fc3..b6f5f4fc56 100644
--- a/src/game/UnitAI.h
+++ b/src/game/UnitAI.h
@@ -22,6 +22,7 @@
 #define TRINITY_UNITAI_H
 
 #include "Platform/Define.h"
+#include "CreatureAIImpl.h"
 
 class Unit;
 class Player;