diff --git a/strategic_player1.h b/strategic_player1.h
index a05d2b5..bdb97ac 100644
--- a/strategic_player1.h
+++ b/strategic_player1.h
@@ -4,6 +4,7 @@
 #include "common.h"
 #include "board.h"
 #include "player.h"
+#include <vector>
 
 class StrategicPlayer1 : public IPlayer {
     char name;