diff --git a/README.md b/README.md
index f4b00b70..9f2fc27c 100644
--- a/README.md
+++ b/README.md
@@ -149,11 +149,11 @@ var CONFIG = {
 
      /* read more in wiki */
      leftBottom: [{ type: SCREENSAVER_ITEMS.DATETIME }],
-     /* slides: Array of paths to pictures. */
+     /* slides: Array of paths to pictures and, optionally, associated CSS classes. */
      slides: [
-       {bg: 'images/bg1.jpeg'},
-       {bg: 'images/bg2.png'},
-       {bg: 'images/bg3.jpg'}
+       {bg: 'images/bg1.jpeg', classes:['-slide1']},
+       {bg: 'images/bg2.png', classes:['-slide2']},
+       {bg: 'images/bg3.jpg', classes:['-slide3']}
      ]
    },
 
diff --git a/scripts/controllers/screensaver.js b/scripts/controllers/screensaver.js
index 0a94ea6d..bdd37f45 100644
--- a/scripts/controllers/screensaver.js
+++ b/scripts/controllers/screensaver.js
@@ -33,6 +33,14 @@ App.controller('Screensaver', function ($scope) {
 
       slide._classes.length = 0;
 
+      let slideClasses = slide.classes;
+      if (slideClasses) {
+         if (!Array.isArray(slideClasses)) {
+            slideClasses = [slideClasses];
+         }
+         slide._classes.push(...slideClasses);
+      }
+
       if (activeSlide === index) {
          slide._classes.push('-active');
       }