diff -r 93e0e89496fe -r 6e39f53127e9 src/chess/fen.c
--- a/src/chess/fen.c	Tue Sep 08 14:34:48 2026 +0200
+++ b/src/chess/fen.c	Tue Sep 08 22:22:01 2026 +0200
@@ -57,6 +57,7 @@
                 case BKNIGHT: str[i++] = 'n'; break;
                 case BROOK: str[i++] = 'r'; break;
                 case BPAWN: str[i++] = 'p'; break;
+                case NOPIECE: /* unreachable */ break;
                 }
             } else {
                 skip++;