diff --git a/lib/media/eme_manager.js b/lib/media/eme_manager.js
index d6e2a17a3..3d0d46257 100644
--- a/lib/media/eme_manager.js
+++ b/lib/media/eme_manager.js
@@ -76,8 +76,8 @@ shaka.media.EmeManager = function(player, video, videoSource) {
   /** @private {!shaka.util.EventManager} */
   this.eventManager_ = new shaka.util.EventManager();
 
-  /** @private {Object.<string, boolean>} */
-  this.requestGenerated_ = {};
+  /** @private {!Array.<!Uint8Array>} */
+  this.requestGenerated_ = [];
 
   /** @private {!Array.<!MediaKeySession>} */
   this.sessions_ = [];
@@ -535,10 +535,13 @@ shaka.media.EmeManager.prototype.onEncrypted_ = function(event) {
   shaka.log.info('onEncrypted_', initData, event);
 
   // Suppress duplicate init data.
-  var initDataKey = shaka.util.Uint8ArrayUtils.key(initData);
-  if (this.requestGenerated_[initDataKey]) {
-    shaka.log.debug('License request already generated!');
-    return;
+  // Note that some init data are extremely large and can't portably be used as
+  // keys in a dictionary.
+  for (var i = 0; i < this.requestGenerated_.length; ++i) {
+    if (shaka.util.Uint8ArrayUtils.equal(initData, this.requestGenerated_[i])) {
+      shaka.log.debug('License request already generated!');
+      return;
+    }
   }
 
   try {
@@ -552,16 +555,22 @@ shaka.media.EmeManager.prototype.onEncrypted_ = function(event) {
 
   var p = session.generateRequest(event.initDataType,
       /** @type {!BufferSource} */(event.initData));
-  this.requestGenerated_[initDataKey] = true;
+  this.requestGenerated_.push(initData);
 
   p.catch(shaka.util.TypedBind(this,
       /** @param {*} error */
       function(error) {
-        if (!this.requestGenerated_) {
+        if (!this.video_) {
           // The EmeManager has already been destroyed.
           return;
         }
-        this.requestGenerated_[initDataKey] = false;
+        for (var i = 0; i < this.requestGenerated_.length; ++i) {
+          if (shaka.util.Uint8ArrayUtils.equal(initData,
+                                               this.requestGenerated_[i])) {
+            this.requestGenerated_.splice(i, 1);
+            break;
+          }
+        }
         var event = shaka.util.FakeEvent.createErrorEvent(error);
         this.dispatchEvent(event);
         this.allSessionsPresumedReady_.reject(error);
diff --git a/lib/player/drm_info.js b/lib/player/drm_info.js
index 5437cb4e3..9994ec98e 100644
--- a/lib/player/drm_info.js
+++ b/lib/player/drm_info.js
@@ -491,18 +491,21 @@ shaka.player.DrmInfo.prototype.addInitDatas = function(
             };
           }));
 
-  /**
-   * @param {!shaka.player.DrmInfo.InitData} initData
-   * @return {string}
-   */
-  var initDataKey = function(initData) {
-    // FIXME: initData.initData may be very large; on some browsers using such
-    // a large string as a key into an object may cause problems.
-    return shaka.util.Uint8ArrayUtils.key(initData.initData) + ',' +
-           initData.initDataType;
-  };
-
   this.initDatas = shaka.util.ArrayUtils.removeDuplicates(
-      unfilteredInitDatas, initDataKey);
+      unfilteredInitDatas, shaka.player.DrmInfo.compareInitDatas_);
+};
+
+
+/**
+ * @param {!shaka.player.DrmInfo.InitData} initDataA
+ * @param {!shaka.player.DrmInfo.InitData} initDataB
+ * @return {boolean}
+ * @private
+ */
+shaka.player.DrmInfo.compareInitDatas_ =
+    function(initDataA, initDataB) {
+  return initDataA.initDataType == initDataB.initDataType &&
+         shaka.util.Uint8ArrayUtils.equal(initDataA.initData,
+                                          initDataB.initData);
 };
 
diff --git a/lib/util/array_utils.js b/lib/util/array_utils.js
index ac9c8999a..5ebdd681f 100644
--- a/lib/util/array_utils.js
+++ b/lib/util/array_utils.js
@@ -25,24 +25,25 @@ goog.provide('shaka.util.ArrayUtils');
 
 
 /**
- * Remove duplicate entries from an array.
+ * Remove duplicate entries from an array.  Order N^2, so use with caution.
  * @param {!Array.<T>} array
- * @param {function(T): (string|number)=} opt_keyFn An optional function which
- *     takes an array item and converts it into a key.  Use this if your array
- *     items cannot be used as an index into an Object.
- * @return {!Array.<T>} A sorted list of the keys.
+ * @param {function(T, T): boolean=} opt_compareFn An optional function which
+ *     will be used to compare items in the array.
+ * @return {!Array.<T>}
  * @template T
  */
-shaka.util.ArrayUtils.removeDuplicates = function(array, opt_keyFn) {
-  var set = {};
-  for (var i = 0; i < array.length; ++i) {
-    var key = opt_keyFn ? opt_keyFn(array[i]) : array[i].toString();
-    set[key] = array[i];
-  }
-
+shaka.util.ArrayUtils.removeDuplicates = function(array, opt_compareFn) {
   var result = [];
-  for (var k in set) {
-    result.push(set[k]);
+  for (var i = 0; i < array.length; ++i) {
+    var matchFound = false;
+    for (var j = 0; j < result.length; ++j) {
+      matchFound = opt_compareFn ? opt_compareFn(array[i], result[j]) :
+                                   array[i] === result[j];
+      if (matchFound) break;
+    }
+    if (!matchFound) {
+      result.push(array[i]);
+    }
   }
   return result;
 };
diff --git a/lib/util/uint8array_utils.js b/lib/util/uint8array_utils.js
index 2b9e63053..c4917357a 100644
--- a/lib/util/uint8array_utils.js
+++ b/lib/util/uint8array_utils.js
@@ -129,13 +129,3 @@ shaka.util.Uint8ArrayUtils.equal = function(arr1, arr2) {
   return true;
 };
 
-
-/**
- * Convert a Uint8Array to a string which can be used as a key in a dictionary.
- * @param {!Uint8Array} arr
- * @return {string}
- */
-shaka.util.Uint8ArrayUtils.key = function(arr) {
-  return Array.prototype.join.apply(arr);
-};
-