--- djbdns-1.05.o/dns_transmit.c	2001-02-11 23:11:45.000000000 +0200
+++ djbdns-1.05/dns_transmit.c	2024-05-27 16:25:11.857369652 +0200
@@ -265,9 +265,9 @@
       if (errno == error_connrefused) if (d->udploop == 2) return 0;
       return nextudp(d);
     }
-    if (r + 1 > sizeof udpbuf) return 0;
 
     if (irrelevant(d,udpbuf,r)) return 0;
+    if ((size_t)r + 1 > sizeof udpbuf) return firsttcp(d); /* if udp overflowed, retry with TCP */
     if (serverwantstcp(udpbuf,r)) return firsttcp(d);
     if (serverfailed(udpbuf,r)) {
       if (d->udploop == 2) return 0;