diff --git a/lib/debug/asserts.js b/lib/debug/asserts.js
index 143a7923c..1cf7866eb 100644
--- a/lib/debug/asserts.js
+++ b/lib/debug/asserts.js
@@ -49,6 +49,7 @@ shaka.asserts.patchAssert_ = function() {
   if (!assert) {
     console.assert = function() {};
   } else if (!assert.bind) {
+    // IE 9 does not provide a .bind for the built-in console functions.
     console.assert = function() {
       assert.apply(console, arguments);
     }
diff --git a/lib/debug/log.js b/lib/debug/log.js
index 97571785c..fdb117cee 100644
--- a/lib/debug/log.js
+++ b/lib/debug/log.js
@@ -76,6 +76,7 @@ shaka.log.patchConsole_ = function(logName) {
   if (!logFunction) {
     console[logName] = nop;
   } else if (!logFunction.bind) {
+    // IE 9 does not provide a .bind for the built-in logging functions.
     console[logName] = function() {
       logFunction.apply(console, arguments);
     }
diff --git a/support.js b/support.js
index 745d934ba..0b3550b2b 100644
--- a/support.js
+++ b/support.js
@@ -304,6 +304,9 @@ if (async.length) {
 }
 
 function onLoaded(fn) {
+  // IE 9 fires DOMContentLoaded, and enters the "interactive"
+  // readyState, before document.body has been initialized, so wait
+  // for window.load
   if (document.readyState == "loading" ||
       document.readyState == "interactive") {
     window.addEventListener('load', fn);