diff --git a/lib/media/content_workarounds.js b/lib/media/content_workarounds.js
index e86ec1f037..6f4b1f7d70 100644
--- a/lib/media/content_workarounds.js
+++ b/lib/media/content_workarounds.js
@@ -188,7 +188,8 @@ shaka.media.ContentWorkarounds = class {
     // patched one, otherwise video element throws following error:
     // CHUNK_DEMUXER_ERROR_APPEND_FAILED: Sample encryption info is not
     // available.
-    if (shaka.util.Platform.isEdge() && shaka.util.Platform.isWindows()) {
+    if (shaka.util.Platform.isEdge() && shaka.util.Platform.isWindows() &&
+        !shaka.util.Platform.isXboxOne()) {
       const doubleInitSegment = new Uint8Array(initSegment.byteLength +
         modifiedInitSegment.byteLength);
       doubleInitSegment.set(modifiedInitSegment);
diff --git a/lib/util/platform.js b/lib/util/platform.js
index 0f06c7ec92..2bdb8daee9 100644
--- a/lib/util/platform.js
+++ b/lib/util/platform.js
@@ -503,7 +503,7 @@ shaka.util.Platform = class {
     if (!navigator.platform) {
       return false;
     }
-    return navigator.platform.toLowerCase().includes('windows');
+    return navigator.platform.toLowerCase().includes('win32');
   }
 
   /**