diff --git a/web/pdf_history.js b/web/pdf_history.js
index 9d345aa2d..4ba506ede 100644
--- a/web/pdf_history.js
+++ b/web/pdf_history.js
@@ -102,7 +102,7 @@ class PDFHistory {
     this._updateUrl = updateUrl === true;
 
     this._initialized = true;
-    this._bindEvents();
+    this.#bindEvents();
     const state = window.history.state;
 
     this._popStateInProgress = false;
@@ -114,19 +114,19 @@ class PDFHistory {
     this._destination = null;
     this._position = null;
 
-    if (!this._isValidState(state, /* checkReload = */ true) || resetHistory) {
-      const { hash, page, rotation } = this._parseCurrentHash(
+    if (!this.#isValidState(state, /* checkReload = */ true) || resetHistory) {
+      const { hash, page, rotation } = this.#parseCurrentHash(
         /* checkNameddest = */ true
       );
 
       if (!hash || reInitialized || resetHistory) {
         // Ensure that the browser history is reset on PDF document load.
-        this._pushOrReplaceState(null, /* forceReplace = */ true);
+        this.#pushOrReplaceState(null, /* forceReplace = */ true);
         return;
       }
       // Ensure that the browser history is initialized correctly when
       // the document hash is present on PDF document load.
-      this._pushOrReplaceState(
+      this.#pushOrReplaceState(
         { hash, page, rotation },
         /* forceReplace = */ true
       );
@@ -136,7 +136,7 @@ class PDFHistory {
     // The browser history contains a valid entry, ensure that the history is
     // initialized correctly on PDF document load.
     const destination = state.destination;
-    this._updateInternalState(
+    this.#updateInternalState(
       destination,
       state.uid,
       /* removeTemporary = */ true
@@ -166,10 +166,10 @@ class PDFHistory {
    */
   reset() {
     if (this._initialized) {
-      this._pageHide(); // Simulate a 'pagehide' event when resetting.
+      this.#pageHide(); // Simulate a 'pagehide' event when resetting.
 
       this._initialized = false;
-      this._unbindEvents();
+      this.#unbindEvents();
     }
     if (this._updateViewareaTimeout) {
       clearTimeout(this._updateViewareaTimeout);
@@ -199,7 +199,7 @@ class PDFHistory {
           `"${explicitDest}" is not a valid explicitDest parameter.`
       );
       return;
-    } else if (!this._isValidPage(pageNumber)) {
+    } else if (!this.#isValidPage(pageNumber)) {
       // Allow an unset `pageNumber` if and only if the history is still empty;
       // please refer to the `this._destination.page = null;` comment above.
       if (pageNumber !== null || this._destination) {
@@ -238,7 +238,7 @@ class PDFHistory {
       return;
     }
 
-    this._pushOrReplaceState(
+    this.#pushOrReplaceState(
       {
         dest: explicitDest,
         hash,
@@ -269,7 +269,7 @@ class PDFHistory {
     if (!this._initialized) {
       return;
     }
-    if (!this._isValidPage(pageNumber)) {
+    if (!this.#isValidPage(pageNumber)) {
       console.error(
         `PDFHistory.pushPage: "${pageNumber}" is not a valid page number.`
       );
@@ -285,8 +285,8 @@ class PDFHistory {
       return;
     }
 
-    this._pushOrReplaceState({
-      // Simulate an internal destination, for `this._tryPushCurrentPosition`:
+    this.#pushOrReplaceState({
+      // Simulate an internal destination, for `this.#tryPushCurrentPosition`:
       dest: null,
       hash: `page=${pageNumber}`,
       page: pageNumber,
@@ -312,7 +312,7 @@ class PDFHistory {
     if (!this._initialized || this._popStateInProgress) {
       return;
     }
-    this._tryPushCurrentPosition();
+    this.#tryPushCurrentPosition();
   }
 
   /**
@@ -324,7 +324,7 @@ class PDFHistory {
       return;
     }
     const state = window.history.state;
-    if (this._isValidState(state) && state.uid > 0) {
+    if (this.#isValidState(state) && state.uid > 0) {
       window.history.back();
     }
   }
@@ -338,7 +338,7 @@ class PDFHistory {
       return;
     }
     const state = window.history.state;
-    if (this._isValidState(state) && state.uid < this._maxUid) {
+    if (this.#isValidState(state) && state.uid < this._maxUid) {
       window.history.forward();
     }
   }
@@ -362,10 +362,7 @@ class PDFHistory {
     return this._initialized ? this._initialRotation : null;
   }
 
-  /**
-   * @private
-   */
-  _pushOrReplaceState(destination, forceReplace = false) {
+  #pushOrReplaceState(destination, forceReplace = false) {
     const shouldReplace = forceReplace || !this._destination;
     const newState = {
       fingerprint: this._fingerprint,
@@ -381,7 +378,7 @@ class PDFHistory {
       // history.state.chromecomState is managed by chromecom.js.
       newState.chromecomState = window.history.state.chromecomState;
     }
-    this._updateInternalState(destination, newState.uid);
+    this.#updateInternalState(destination, newState.uid);
 
     let newUrl;
     if (this._updateUrl && destination?.hash) {
@@ -407,10 +404,7 @@ class PDFHistory {
     }
   }
 
-  /**
-   * @private
-   */
-  _tryPushCurrentPosition(temporary = false) {
+  #tryPushCurrentPosition(temporary = false) {
     if (!this._position) {
       return;
     }
@@ -421,12 +415,12 @@ class PDFHistory {
     }
 
     if (!this._destination) {
-      this._pushOrReplaceState(position);
+      this.#pushOrReplaceState(position);
       return;
     }
     if (this._destination.temporary) {
       // Always replace a previous *temporary* position.
-      this._pushOrReplaceState(position, /* forceReplace = */ true);
+      this.#pushOrReplaceState(position, /* forceReplace = */ true);
       return;
     }
     if (this._destination.hash === position.hash) {
@@ -460,22 +454,16 @@ class PDFHistory {
       // To avoid "flooding" the browser history, replace the current entry.
       forceReplace = true;
     }
-    this._pushOrReplaceState(position, forceReplace);
+    this.#pushOrReplaceState(position, forceReplace);
   }
 
-  /**
-   * @private
-   */
-  _isValidPage(val) {
+  #isValidPage(val) {
     return (
       Number.isInteger(val) && val > 0 && val <= this.linkService.pagesCount
     );
   }
 
-  /**
-   * @private
-   */
-  _isValidState(state, checkReload = false) {
+  #isValidState(state, checkReload = false) {
     if (!state) {
       return false;
     }
@@ -508,10 +496,7 @@ class PDFHistory {
     return true;
   }
 
-  /**
-   * @private
-   */
-  _updateInternalState(destination, uid, removeTemporary = false) {
+  #updateInternalState(destination, uid, removeTemporary = false) {
     if (this._updateViewareaTimeout) {
       // When updating `this._destination`, make sure that we always wait for
       // the next 'updateviewarea' event before (potentially) attempting to
@@ -531,26 +516,20 @@ class PDFHistory {
     this._numPositionUpdates = 0;
   }
 
-  /**
-   * @private
-   */
-  _parseCurrentHash(checkNameddest = false) {
+  #parseCurrentHash(checkNameddest = false) {
     const hash = unescape(getCurrentHash()).substring(1);
     const params = parseQueryString(hash);
 
     const nameddest = params.get("nameddest") || "";
     let page = params.get("page") | 0;
 
-    if (!this._isValidPage(page) || (checkNameddest && nameddest.length > 0)) {
+    if (!this.#isValidPage(page) || (checkNameddest && nameddest.length > 0)) {
       page = null;
     }
     return { hash, page, rotation: this.linkService.rotation };
   }
 
-  /**
-   * @private
-   */
-  _updateViewarea({ location }) {
+  #updateViewarea({ location }) {
     if (this._updateViewareaTimeout) {
       clearTimeout(this._updateViewareaTimeout);
       this._updateViewareaTimeout = null;
@@ -575,9 +554,9 @@ class PDFHistory {
     ) {
       // If the current destination was set through the user changing the hash
       // of the document, we will usually not try to push the current position
-      // to the browser history; see `this._tryPushCurrentPosition()`.
+      // to the browser history; see `this.#tryPushCurrentPosition()`.
       //
-      // To prevent `this._tryPushCurrentPosition()` from effectively being
+      // To prevent `this.#tryPushCurrentPosition()` from effectively being
       // reduced to a no-op in this case, we will assume that the position
       // *did* in fact change if the 'updateviewarea' event was dispatched
       // more than `POSITION_UPDATED_THRESHOLD` times.
@@ -602,17 +581,14 @@ class PDFHistory {
       // the viewer has been idle for `UPDATE_VIEWAREA_TIMEOUT` milliseconds.
       this._updateViewareaTimeout = setTimeout(() => {
         if (!this._popStateInProgress) {
-          this._tryPushCurrentPosition(/* temporary = */ true);
+          this.#tryPushCurrentPosition(/* temporary = */ true);
         }
         this._updateViewareaTimeout = null;
       }, UPDATE_VIEWAREA_TIMEOUT);
     }
   }
 
-  /**
-   * @private
-   */
-  _popState({ state }) {
+  #popState({ state }) {
     const newHash = getCurrentHash(),
       hashChanged = this._currentHash !== newHash;
     this._currentHash = newHash;
@@ -621,20 +597,20 @@ class PDFHistory {
       (typeof PDFJSDev !== "undefined" &&
         PDFJSDev.test("CHROME") &&
         state?.chromecomState &&
-        !this._isValidState(state)) ||
+        !this.#isValidState(state)) ||
       !state
     ) {
       // This case corresponds to the user changing the hash of the document.
       this._uid++;
 
-      const { hash, page, rotation } = this._parseCurrentHash();
-      this._pushOrReplaceState(
+      const { hash, page, rotation } = this.#parseCurrentHash();
+      this.#pushOrReplaceState(
         { hash, page, rotation },
         /* forceReplace = */ true
       );
       return;
     }
-    if (!this._isValidState(state)) {
+    if (!this.#isValidState(state)) {
       // This should only occur in viewers with support for opening more than
       // one PDF document, e.g. the GENERIC viewer.
       return;
@@ -666,7 +642,7 @@ class PDFHistory {
 
     // Navigate to the new destination.
     const destination = state.destination;
-    this._updateInternalState(
+    this.#updateInternalState(
       destination,
       state.uid,
       /* removeTemporary = */ true
@@ -691,31 +667,25 @@ class PDFHistory {
     });
   }
 
-  /**
-   * @private
-   */
-  _pageHide() {
+  #pageHide() {
     // Attempt to push the `this._position` into the browser history when
     // navigating away from the document. This is *only* done if the history
     // is empty/temporary, since otherwise an existing browser history entry
     // will end up being overwritten (given that new entries cannot be pushed
     // into the browser history when the 'unload' event has already fired).
     if (!this._destination || this._destination.temporary) {
-      this._tryPushCurrentPosition();
+      this.#tryPushCurrentPosition();
     }
   }
 
-  /**
-   * @private
-   */
-  _bindEvents() {
+  #bindEvents() {
     if (this._boundEvents) {
       return; // The event listeners were already added.
     }
     this._boundEvents = {
-      updateViewarea: this._updateViewarea.bind(this),
-      popState: this._popState.bind(this),
-      pageHide: this._pageHide.bind(this),
+      updateViewarea: this.#updateViewarea.bind(this),
+      popState: this.#popState.bind(this),
+      pageHide: this.#pageHide.bind(this),
     };
 
     this.eventBus._on("updateviewarea", this._boundEvents.updateViewarea);
@@ -723,10 +693,7 @@ class PDFHistory {
     window.addEventListener("pagehide", this._boundEvents.pageHide);
   }
 
-  /**
-   * @private
-   */
-  _unbindEvents() {
+  #unbindEvents() {
     if (!this._boundEvents) {
       return; // The event listeners were already removed.
     }