diff --git a/lib/player/player.js b/lib/player/player.js
index 322825b164..a7abc6166c 100644
--- a/lib/player/player.js
+++ b/lib/player/player.js
@@ -746,13 +746,13 @@ shaka.player.Player.prototype.setPlaybackRate = function(rate) {
  *     For example: A Restrictions instance with maxBandwidth = 700000
  *     and minBandwidth = 200000 will restrict
  *     playback to video tracks with bandwidth between 700000 and 200000.
+ * @throws {TypeError} if restrictions argument isn't a Restrictions instance.
  * @export
  */
 shaka.player.Player.prototype.setRestrictions = function(restrictions) {
-  shaka.asserts
-    .assert(restrictions instanceof shaka.player.DrmSchemeInfo.Restrictions);
-  if (!(restrictions instanceof shaka.player.DrmSchemeInfo.Restrictions))
-    return;
+  if (!(restrictions instanceof shaka.player.DrmSchemeInfo.Restrictions)) {
+    throw new TypeError('Argument must be a Restrictions instance.');
+  }
   this.restrictions_ = restrictions;
   this.videoSource_.setRestrictions(this.restrictions_);
 };