--- a/command.c	Thu Dec 29 22:28:19 2005 +0000
+++ b/command.c	Fri Dec 30 14:28:32 2005 +0000
@@ -332,7 +332,7 @@
 	CommandProc *proc;
 
 	/* Do not even think about executing out-of-bounds tile-commands */
-	if (TileVirtXY(x, y) > MapSize()) {
+	if (TileVirtXY(x, y) >= MapSize()) {
 		_cmd_text = NULL;
 		return CMD_ERROR;
 	}