diff --git a/src/warden-server/bin/registerSender.pl b/src/warden-server/bin/registerSender.pl
index fc7d48b51bc754f0064cecfcb899255abff06ead..595831dce9857ce1b2338b91f24c7171da74d8bf 100755
--- a/src/warden-server/bin/registerSender.pl
+++ b/src/warden-server/bin/registerSender.pl
@@ -119,7 +119,7 @@ switch () {
 
 # check validity of IP address (CIDR format)
 if ($ip_net_client !~ /^(([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])\.){3}([0-9]|[1-9][0-9]|1[0-9]{2}|2[0-4][0-9]|25[0-5])(\/(\d|[1-2]\d|3[0-2]))$/) {
-  WardenCommon::errMsg("Enter correct IP in CIDR format!");
+  WardenCommon::errMsg("Incorrect CIDR format of IP address: '$ip_net_client'!");
 }
 
 # check client ID