diff --git a/cd.sh b/cd.sh
index 4ef96ea..8d3a52c 100644
--- a/cd.sh
+++ b/cd.sh
@@ -107,7 +107,7 @@ local server
 local servers
 local text=""
     cd_step "Set DNS resolving"
-    "${CD_DNS}" && servers="${CD_DNS}" || servers="${CD_DEFAULT_DNS}"
+    [ "${CD_DNS}" ] && servers="${CD_DNS}" || servers="${CD_DEFAULT_DNS}"
     for server in ${servers} ; do
         text="${text}nameserver ${server}
 "