diff --git a/src/fast-chess.c b/src/fast-chess.c
index b60be58..c7c6666 100644
--- a/src/fast-chess.c
+++ b/src/fast-chess.c
@@ -1258,10 +1258,10 @@ BOOL canCastleKingside(Position * position, char color) {
 
 	case WHITE:
 		if ( (position->castlingRights&CASTLE_KINGSIDE_WHITE) &&
-			 (position->board[str2index("e1")] == WHITE|KING) &&
+			 (position->board[str2index("e1")] == (WHITE|KING)) &&
 			 (position->board[str2index("f1")] == EMPTY) &&
 			 (position->board[str2index("g1")] == EMPTY) &&
-			 (position->board[str2index("h1")] == WHITE|ROOK) &&
+			 (position->board[str2index("h1")] == (WHITE|ROOK)) &&
 			 (!isAttacked(str2bb("e1"), position->board, opponent(color))) &&
 			 (!isAttacked(str2bb("f1"), position->board, opponent(color))) &&
 			 (!isAttacked(str2bb("g1"), position->board, opponent(color))) )
@@ -1271,10 +1271,10 @@ BOOL canCastleKingside(Position * position, char color) {
 
 	case BLACK:
 		if ( (position->castlingRights&CASTLE_KINGSIDE_BLACK) &&
-			 (position->board[str2index("e8")] == BLACK|KING) &&
+			 (position->board[str2index("e8")] == (BLACK|KING)) &&
 			 (position->board[str2index("f8")] == EMPTY) &&
 			 (position->board[str2index("g8")] == EMPTY) &&
-			 (position->board[str2index("h8")] == BLACK|ROOK) &&
+			 (position->board[str2index("h8")] == (BLACK|ROOK)) &&
 			 (!isAttacked(str2bb("e8"), position->board, opponent(color))) &&
 			 (!isAttacked(str2bb("f8"), position->board, opponent(color))) &&
 			 (!isAttacked(str2bb("g8"), position->board, opponent(color))) )
@@ -1291,11 +1291,11 @@ BOOL canCastleQueenside(Position * position, char color) {
 
 	case WHITE:
 		if ( (position->castlingRights&CASTLE_QUEENSIDE_WHITE) &&
-			 (position->board[str2index("a1")] == WHITE|ROOK) &&
+			 (position->board[str2index("a1")] == (WHITE|ROOK)) &&
 			 (position->board[str2index("b1")] == EMPTY) &&
 			 (position->board[str2index("c1")] == EMPTY) &&
 			 (position->board[str2index("d1")] == EMPTY) &&
-			 (position->board[str2index("e1")] == WHITE|KING) &&
+			 (position->board[str2index("e1")] == (WHITE|KING)) &&
 			 (!isAttacked(str2bb("c1"), position->board, opponent(color))) &&
 			 (!isAttacked(str2bb("d1"), position->board, opponent(color))) &&
 			 (!isAttacked(str2bb("e1"), position->board, opponent(color))) )
@@ -1305,11 +1305,11 @@ BOOL canCastleQueenside(Position * position, char color) {
 
 	case BLACK:
 		if ( (position->castlingRights&CASTLE_QUEENSIDE_BLACK) &&
-				 (position->board[str2index("a8")] == BLACK|ROOK) &&
+				 (position->board[str2index("a8")] == (BLACK|ROOK)) &&
 				 (position->board[str2index("b8")] == EMPTY) &&
 				 (position->board[str2index("c8")] == EMPTY) &&
 				 (position->board[str2index("d8")] == EMPTY) &&
-				 (position->board[str2index("e8")] == BLACK|KING) &&
+				 (position->board[str2index("e8")] == (BLACK|KING)) &&
 				 (!isAttacked(str2bb("c8"), position->board, opponent(color))) &&
 				 (!isAttacked(str2bb("d8"), position->board, opponent(color))) &&
 				 (!isAttacked(str2bb("e8"), position->board, opponent(color))) )