diff --git a/layouts/_default/baseof.html b/layouts/_default/baseof.html
index 612b265..1172796 100644
--- a/layouts/_default/baseof.html
+++ b/layouts/_default/baseof.html
@@ -95,7 +95,7 @@
   {{ else if eq .Site.Params.colorscheme "auto" }}
     {{ $csClass = "colorscheme-auto" }}
   {{ end }}
-  <body class="{{ .Kind | lower }} {{ .File.BaseFileName | lower }} {{ $csClass }}{{ if .Site.Params.rtl }} rtl{{ end }}">
+  <body class="{{ .Kind | lower }} {{ with .File }}{{ .BaseFileName | lower }}{{ end }} {{ $csClass }}{{ if .Site.Params.rtl }} rtl{{ end }}">
     <main class="wrapper">
       {{ partial "header.html" . }}
 
