diff --git a/layouts/_default/baseof.html b/layouts/_default/baseof.html
index 94c5673..b8cfb07 100644
--- a/layouts/_default/baseof.html
+++ b/layouts/_default/baseof.html
@@ -5,7 +5,7 @@
   <body>
     {{ if .IsHome }}
     {{ "<!-- header -->" | safeHTML }}
-    <header class="banner overlay bg-cover" data-background="{{ .Site.Params.banner.bg_image | absURL }}">
+    <header class="banner {{if .Site.Params.banner.bg_image}}overlay bg-cover{{else}}bg-primary{{end}}" data-background="{{ .Site.Params.banner.bg_image | absURL }}">
       {{ partial "navigation.html" . }}
       {{ partial "banner.html" . }}
     </header>
