diff --git a/js/controllers/autoanimate.js b/js/controllers/autoanimate.js
index 20151904..9204524c 100644
--- a/js/controllers/autoanimate.js
+++ b/js/controllers/autoanimate.js
@@ -1,5 +1,9 @@
 import { extend, toArray, createStyleSheet } from '../utils/util.js'
 
+/**
+ * Automatically animates matching elements across
+ * slides with the [data-auto-animate] attribute.
+ */
 export default class AutoAnimate {
 
 	constructor( Reveal ) {
diff --git a/js/controllers/slidecontent.js b/js/controllers/slidecontent.js
index 2285b295..ec2aa716 100644
--- a/js/controllers/slidecontent.js
+++ b/js/controllers/slidecontent.js
@@ -1,6 +1,10 @@
 import { HORIZONTAL_SLIDES_SELECTOR, VERTICAL_SLIDES_SELECTOR } from '../utils/constants.js'
 import { extend, toArray, closestParent } from '../utils/util.js'
 
+/**
+ * Handles loading, unloading and playback of slide
+ * content such as images, videos and iframes.
+ */
 export default class SlideContent {
 
 	constructor( Reveal ) {