diff --git a/lib/ads/interstitial_ad_manager.js b/lib/ads/interstitial_ad_manager.js
index 5e6ab733f1..ea2f7fbf14 100644
--- a/lib/ads/interstitial_ad_manager.js
+++ b/lib/ads/interstitial_ad_manager.js
@@ -212,6 +212,10 @@ shaka.ads.InterstitialAdManager = class {
     if (this.adContainer_) {
       shaka.util.Dom.removeAllChildren(this.adContainer_);
     }
+    if (this.pollTimer_) {
+      this.pollTimer_.stop();
+      this.pollTimer_ = null;
+    }
     this.player_.destroy();
   }