diff --git a/lib/ads/interstitial_ad_manager.js b/lib/ads/interstitial_ad_manager.js
index 2ec6984dad..c021f485bf 100644
--- a/lib/ads/interstitial_ad_manager.js
+++ b/lib/ads/interstitial_ad_manager.js
@@ -922,7 +922,7 @@ shaka.ads.InterstitialAdManager = class {
               skipOffset = isSkippable ? 0 : null;
             }
           }
-          const enableSkipForValue = skipControl['X-ENABLE-SKIP-FOR'];
+          const enableSkipForValue = skipControl['ENABLE-SKIP-FOR'];
           if (enableSkipForValue instanceof Number) {
             skipFor = parseFloat(enableSkipForValue);
             if (isNaN(enableSkipForValue)) {