diff -r f0fc70b6f8f9 -r 2a6d83f4677e src/chess/bishop.c
--- a/src/chess/bishop.c	Thu Jul 30 18:34:15 2026 +0200
+++ b/src/chess/bishop.c	Thu Jul 30 19:17:38 2026 +0200
@@ -31,11 +31,11 @@
 #include "rules.h"
 #include <stdlib.h>
 
-bool bishop_chkrules(Move* move) {
+bool bishop_chkrules(const Move* move) {
     return abs(move->torow-move->fromrow) == abs(move->tofile-move->fromfile);
 }
 
-bool bishop_isblocked(GameState *gamestate, Move *move) {
+bool bishop_isblocked(const GameState *gamestate, const Move *move) {
     int dy = move->torow > move->fromrow ? 1 : -1;
     int dx = move->tofile > move->fromfile ? 1 : -1;