diff --git a/README.md b/README.md
index 6ef6529..aec5fc1 100644
--- a/README.md
+++ b/README.md
@@ -234,7 +234,7 @@ Name | URL
 ------------------------------------ | ---------------------------------------------
 BGP Toolkit | http://bgp.he.net/ :+1:
 TCP utils | http://www.tcpiputils.com/
-Ultra tools | https://www.ultratools.com/tools/asnInfo
+DNS Checker | https://dnschecker.org/asn-whois-lookup.php
 IP research | https://whatismyipaddress.com/
 Black list | https://mxtoolbox.com/blacklists.aspx
 extract_hosts6.sh | https://github.com/vanhauser-thc/thc-ipv6/blob/master/extract_hosts6.sh