diff --git a/unmovable_cmd.c b/unmovable_cmd.c
--- a/unmovable_cmd.c
+++ b/unmovable_cmd.c
@@ -389,7 +389,7 @@ static void ChangeTileOwner_Unmovable(Ti
 {
 	if (!IsTileOwner(tile, old_player)) return;
 
-	if (_m[tile].m5==3 && new_player != 255) {
+	if (_m[tile].m5 == 3 && new_player != OWNER_SPECTATOR) {
 		SetTileOwner(tile, new_player);
 	} else {
 		DoClearSquare(tile);