diff --git a/css/reveal.css b/css/reveal.css
index d2cb1be0363a2b1c42441806368c0367f782fe8f..116d3154ad46784a807a7106e9da9b473b058816 100644
--- a/css/reveal.css
+++ b/css/reveal.css
@@ -47,6 +47,12 @@ body {
   background-color: #fff;
   color: #000; }
 
+html:-webkit-full-screen-ancestor {
+  background-color: inherit; }
+
+html:-moz-full-screen-ancestor {
+  background-color: inherit; }
+
 /*********************************************
  * VIEW FRAGMENTS
  *********************************************/
diff --git a/css/reveal.scss b/css/reveal.scss
index 330551b4ee557379ee0cd2f35f6acfb36c4d25cb..2b1546f371fe9940438cbcb52edc86fa36c3fb40 100644
--- a/css/reveal.scss
+++ b/css/reveal.scss
@@ -57,6 +57,15 @@ body {
 	color: #000;
 }
 
+// Ensures that the main background color matches the
+// theme in fullscreen mode
+html:-webkit-full-screen-ancestor {
+	background-color: inherit;
+}
+html:-moz-full-screen-ancestor {
+	background-color: inherit;
+}
+
 
 /*********************************************
  * VIEW FRAGMENTS