diff --git a/lib/polyfill/patchedmediakeys_apple.js b/lib/polyfill/patchedmediakeys_apple.js
index 95e875caca..fc47d6ff5e 100644
--- a/lib/polyfill/patchedmediakeys_apple.js
+++ b/lib/polyfill/patchedmediakeys_apple.js
@@ -27,38 +27,39 @@ goog.require('shaka.util.StringUtils');
 shaka.polyfill.PatchedMediaKeysApple = class {
   /**
    * Installs the polyfill if needed.
-   * @param {boolean} enableUninstall enables uninstalling the polyfill
+   * @param {boolean=} enableUninstall enables uninstalling the polyfill
    * @export
    */
   static install(enableUninstall = false) {
+    // Alias
+    const PatchedMediaKeysApple = shaka.polyfill.PatchedMediaKeysApple;
+
     if (!window.HTMLVideoElement || !window.WebKitMediaKeys) {
       // No HTML5 video or no prefixed EME.
       return;
     }
 
     if (enableUninstall) {
-      this.enableUninstall = true;
-      this.originalHTMLMediaElementPrototypeMediaKeys =
+      PatchedMediaKeysApple.enableUninstall = true;
+      PatchedMediaKeysApple.originalHTMLMediaElementPrototypeMediaKeys =
         /** @type {!Object} */ (
           Object.getOwnPropertyDescriptor(
               // eslint-disable-next-line no-restricted-syntax
               HTMLMediaElement.prototype, 'mediaKeys',
           )
         );
-      // eslint-disable-next-line no-restricted-syntax
-      this.originalHTMLMediaElementPrototypeSetMediaKeys = HTMLMediaElement
-          .prototype.setMediaKeys;
-      this.originalWindowMediaKeys = window.MediaKeys;
-      this.originalWindowMediaKeySystemAccess = window.MediaKeySystemAccess;
-      this.originalNavigatorRequestMediaKeySystemAccess = navigator
-          .requestMediaKeySystemAccess;
+      PatchedMediaKeysApple.originalHTMLMediaElementPrototypeSetMediaKeys =
+          // eslint-disable-next-line no-restricted-syntax
+          HTMLMediaElement.prototype.setMediaKeys;
+      PatchedMediaKeysApple.originalWindowMediaKeys = window.MediaKeys;
+      PatchedMediaKeysApple.originalWindowMediaKeySystemAccess =
+          window.MediaKeySystemAccess;
+      PatchedMediaKeysApple.originalNavigatorRequestMediaKeySystemAccess =
+          navigator.requestMediaKeySystemAccess;
     }
 
     shaka.log.info('Using Apple-prefixed EME');
 
-    // Alias
-    const PatchedMediaKeysApple = shaka.polyfill.PatchedMediaKeysApple;
-
     // Delete mediaKeys to work around strict mode compatibility issues.
     // eslint-disable-next-line no-restricted-syntax
     delete HTMLMediaElement.prototype['mediaKeys'];
@@ -83,32 +84,36 @@ shaka.polyfill.PatchedMediaKeysApple = class {
    * @export
    */
   static uninstall() {
-    if (!this.enableUninstall) {
+    // Alias
+    const PatchedMediaKeysApple = shaka.polyfill.PatchedMediaKeysApple;
+
+    if (!PatchedMediaKeysApple.enableUninstall) {
       return;
     }
 
     shaka.log.info('Un-installing Apple-prefixed EME');
 
-    this.enableUninstall = false;
+    PatchedMediaKeysApple.enableUninstall = false;
     Object.defineProperty(
         // eslint-disable-next-line no-restricted-syntax
         HTMLMediaElement.prototype,
         'mediaKeys',
-        this.originalHTMLMediaElementPrototypeMediaKeys,
+        PatchedMediaKeysApple.originalHTMLMediaElementPrototypeMediaKeys,
     );
     // eslint-disable-next-line no-restricted-syntax
-    HTMLMediaElement.prototype.setMediaKeys = this
-        .originalHTMLMediaElementPrototypeSetMediaKeys;
-    window.MediaKeys = this.originalWindowMediaKeys;
-    window.MediaKeySystemAccess = this.originalWindowMediaKeySystemAccess;
-    navigator.requestMediaKeySystemAccess = this
-        .originalNavigatorRequestMediaKeySystemAccess;
-
-    this.originalWindowMediaKeys = null;
-    this.originalWindowMediaKeySystemAccess = null;
-    this.originalHTMLMediaElementPrototypeSetMediaKeys = null;
-    this.originalNavigatorRequestMediaKeySystemAccess = null;
-    this.originalHTMLMediaElementPrototypeMediaKeys = null;
+    HTMLMediaElement.prototype.setMediaKeys =
+        PatchedMediaKeysApple.originalHTMLMediaElementPrototypeSetMediaKeys;
+    window.MediaKeys = PatchedMediaKeysApple.originalWindowMediaKeys;
+    window.MediaKeySystemAccess =
+        PatchedMediaKeysApple.originalWindowMediaKeySystemAccess;
+    navigator.requestMediaKeySystemAccess =
+        PatchedMediaKeysApple.originalNavigatorRequestMediaKeySystemAccess;
+
+    PatchedMediaKeysApple.originalWindowMediaKeys = null;
+    PatchedMediaKeysApple.originalWindowMediaKeySystemAccess = null;
+    PatchedMediaKeysApple.originalHTMLMediaElementPrototypeSetMediaKeys = null;
+    PatchedMediaKeysApple.originalNavigatorRequestMediaKeySystemAccess = null;
+    PatchedMediaKeysApple.originalHTMLMediaElementPrototypeMediaKeys = null;
 
     window.shakaMediaKeysPolyfill = false;
   }