diff --git a/layouts/_default/baseof.html b/layouts/_default/baseof.html
index 612bddbb2c..6b384fb294 100644
--- a/layouts/_default/baseof.html
+++ b/layouts/_default/baseof.html
@@ -1,6 +1,9 @@
 <!doctype html>
 <html lang="{{ .Site.Language.Lang }}" class="{{.Params.class}} no-js">
-  <head>
+{{- if eq hugo.Environment "preview" -}}
+  <!-- deploy preview -->
+{{- end -}}
+  <head {{- if hugo.IsProduction -}}class="live-site"{{- end -}}>
     {{ partial "head.html" . }}
   </head>
   <body class="td-{{ .Kind }}{{- if ne .Params.cid "" -}}{{- printf " cid-%s" (lower .Params.cid) -}}{{- end -}}">
