diff --git a/cd.sh b/cd.sh
index b31afb0..7a780e3 100644
--- a/cd.sh
+++ b/cd.sh
@@ -1,13 +1,15 @@
 #! /usr/bin/env sh
 
+[ "${CD_DNS}" ] || CD_DNS="\
+9.9.9.9 \
+"
 # modules
 set "cd" "rwx"
 
 # steps
 cd_main () {
     cd_set_environment
-    cd_set_dns_resolving \
-    "9.9.9.9"
+    cd_set_dns_resolving ${CD_DNS}
     cd_set_packages_repositories
     cd_set_packages_configuration
     cd_set_https_verification_off