diff --git a/lib/revalidator.js b/lib/revalidator.js
index 58476b0..9183109 100644
--- a/lib/revalidator.js
+++ b/lib/revalidator.js
@@ -129,7 +129,7 @@
     //'style':        (not supported)
     //'phone':        (not supported)
     //'uri':          (not supported)
-    'host-name':      /^(([a-zA-Z]|[a-zA-Z][a-zA-Z0-9\-]*[a-zA-Z0-9])\.)*([A-Za-z]|[A-Za-z][A-Za-z0-9\-]*[A-Za-z0-9])/,
+    'host-name':      /^(([a-zA-Z0-9]|[a-zA-Z0-9][a-zA-Z0-9\-]*[a-zA-Z0-9])\.)*([A-Za-z0-9]|[A-Za-z0-9][A-Za-z0-9\-]*[A-Za-z0-9])/,
     'utc-millisec':   {
       test: function (value) {
         return typeof(value) === 'number' && value >= 0;