diff --git a/cpp/src/board.hpp b/cpp/src/board.hpp
index cf93651..eafe182 100644
--- a/cpp/src/board.hpp
+++ b/cpp/src/board.hpp
@@ -4,7 +4,7 @@
 
 #include <string>
 
-enum CastleRights {
+enum CastleRights : int8_t {
     KingSide = 1,
     QueenSide = 2,
 };
@@ -13,7 +13,8 @@ class Board {
   private:
     int8_t squares[64] = {Piece::None};
     Colour turn;
-    int8_t castle_rights;
+    int8_t w_castle_rights;
+    int8_t b_castle_rights;
 
   public:
     static Board* setup_fen_position(std::string fen);
diff --git a/cpp/src/piece.hpp b/cpp/src/piece.hpp
index 48f58cb..4631099 100644
--- a/cpp/src/piece.hpp
+++ b/cpp/src/piece.hpp
@@ -1,4 +1,6 @@
-enum Piece {
+#include <cstdint>
+
+enum Piece : int8_t {
     None = 0,
     King = 1,
     Pawn = 2,
@@ -8,7 +10,7 @@ enum Piece {
     Queen = 6,
 };
 
-enum Colour {
+enum Colour : int8_t {
     White = 8,
     Black = 16,
 };