diff --git a/lib/ads/interstitial_ad_manager.js b/lib/ads/interstitial_ad_manager.js
index e116933447..31ff6c916f 100644
--- a/lib/ads/interstitial_ad_manager.js
+++ b/lib/ads/interstitial_ad_manager.js
@@ -737,6 +737,7 @@ shaka.ads.InterstitialAdManager = class {
       document.createElement(tagName));
     htmlElement.style.objectFit = 'contain';
     htmlElement.style.position = 'absolute';
+    htmlElement.style.border = 'none';
 
     const basicTask = () => {
       if (this.playoutLimitTimer_) {