diff --git a/plugins/common/functions b/plugins/common/functions
index 2952ee25d..dad241b5a 100755
--- a/plugins/common/functions
+++ b/plugins/common/functions
@@ -1065,7 +1065,7 @@ strip_inline_comments() {
 
 is_valid_hostname() {
   declare desc="return 0 if argument is a valid hostname; else return 1"
-  local hostname_string="${1,,}"; local hostname_regex='^(([a-z0-9\*](-?[a-z0-9])*)\.)*[a-z0-9\*](-?[a-z0-9])+\.[a-z]{2,}$'
+  local hostname_string="${1,,}"; local hostname_regex='^(([a-z0-9\*](-?[a-z0-9])*)\.)+([a-z0-9\*](-?[a-z0-9])*)$'
   if [[ $hostname_string =~ $hostname_regex ]]; then
     return 0
   else