--- a/misc_cmd.c	Mon Dec 27 18:18:44 2004 +0000
+++ b/misc_cmd.c	Tue Dec 28 09:24:02 2004 +0000
@@ -285,6 +285,11 @@
 {
 	SET_EXPENSES_TYPE(EXPENSES_OTHER);
 
+	p1 = clamp(p1, 0, 0xFFFFFFFF); // Clamp between 4 billion and 0
+
+	if (p1 == 0)
+		return CMD_ERROR;
+
 	if (flags & DC_EXEC) {
 		// Add money to player
 		byte old_cp = _current_player;