diff --git a/fe/dns.go b/fe/dns.go
index e52fa49c74564fe8be013ab7b27daf5bfbd9479d..77c3f2d58ce9096ac321c06ba68d905c7de527b7 100644
--- a/fe/dns.go
+++ b/fe/dns.go
@@ -177,6 +177,11 @@ func (d *DnsRedirector) serveDNS(w dns.ResponseWriter, req *dns.Msg) {
 			m.Answer = append(m.Answer, rec)
 		}
 		responseMsg = fmt.Sprintf("%v", ips)
+
+	default:
+		// Return an error for anything else.
+		m.SetRcode(req, dns.RcodeNameError)
+		responseMsg = "NXDOMAIN"
 	}
 
 	log.Printf("[%d] %s.%s %s (from %s) -> %s", req.MsgHdr.Id, query, d.origin, dns.TypeToString[req.Question[0].Qtype], w.RemoteAddr(), responseMsg)