diff --git a/ext/fg/js/frame-offset-forwarder.js b/ext/fg/js/frame-offset-forwarder.js
index b3715c2a..09eb89a6 100644
--- a/ext/fg/js/frame-offset-forwarder.js
+++ b/ext/fg/js/frame-offset-forwarder.js
@@ -22,15 +22,23 @@
 
 class FrameOffsetForwarder {
     constructor() {
-        this._forwardFrameOffset = window !== window.parent ?
+        this._started = false;
+
+        this._forwardFrameOffset = (
+            window !== window.parent ?
             this._forwardFrameOffsetParent.bind(this) :
-            this._forwardFrameOffsetOrigin.bind(this);
+            this._forwardFrameOffsetOrigin.bind(this)
+        );
 
         this._windowMessageHandlers = new Map([
-            ['getFrameOffset', ({offset, uniqueId}, e) => { return this._onGetFrameOffset(offset, uniqueId, e); }]
+            ['getFrameOffset', ({offset, uniqueId}, e) => this._onGetFrameOffset(offset, uniqueId, e)]
         ]);
+    }
 
+    start() {
+        if (this._started) { return; }
         window.addEventListener('message', this.onMessage.bind(this), false);
+        this._started = true;
     }
 
     async applyOffset(x, y) {
@@ -44,7 +52,6 @@ class FrameOffsetForwarder {
                 chrome.runtime.onMessage.removeListener(runtimeMessageCallback);
                 callback();
                 frameOffsetResolve(params);
-                return false;
             }
         };
         chrome.runtime.onMessage.addListener(runtimeMessageCallback);
diff --git a/ext/fg/js/frontend-initialize.js b/ext/fg/js/frontend-initialize.js
index 777291fe..51fa8d7a 100644
--- a/ext/fg/js/frontend-initialize.js
+++ b/ext/fg/js/frontend-initialize.js
@@ -40,23 +40,26 @@ async function main() {
                 chrome.runtime.onMessage.removeListener(runtimeMessageCallback);
                 callback();
                 rootPopupInformationResolve(params);
-                return false;
             }
         };
         chrome.runtime.onMessage.addListener(runtimeMessageCallback);
-        apiForward('rootPopupInformationGet');
+        apiForward('rootPopupRequestInformationBroadcast');
 
         const {popupId, frameId} = await rootPopupInformationPromise;
 
-        window._frameOffsetForwarder = new FrameOffsetForwarder();
-        const applyFrameOffset = window._frameOffsetForwarder.applyOffset.bind(window._frameOffsetForwarder);
+        const frameOffsetForwarder = new FrameOffsetForwarder();
+        frameOffsetForwarder.start();
+        const applyFrameOffset = frameOffsetForwarder.applyOffset.bind(frameOffsetForwarder);
+
         popup = new PopupProxy(popupId, 0, null, frameId, url, applyFrameOffset);
         await popup.prepare();
     } else if (proxy) {
         popup = new PopupProxy(null, depth + 1, id, parentFrameId, url);
         await popup.prepare();
     } else {
-        window._frameOffsetForwarder = new FrameOffsetForwarder();
+        const frameOffsetForwarder = new FrameOffsetForwarder();
+        frameOffsetForwarder.start();
+
         const popupHost = new PopupProxyHost();
         await popupHost.prepare();
 
diff --git a/ext/fg/js/frontend.js b/ext/fg/js/frontend.js
index d6fe7af4..c160b9e3 100644
--- a/ext/fg/js/frontend.js
+++ b/ext/fg/js/frontend.js
@@ -53,7 +53,7 @@ class Frontend extends TextScanner {
 
         this._runtimeMessageHandlers = new Map([
             ['popupSetVisibleOverride', ({visible}) => { this.popup.setVisibleOverride(visible); }],
-            ['rootPopupInformationGet', () => { this.popup.broadcastRootPopupInformation(); }]
+            ['rootPopupRequestInformationBroadcast', () => { this.popup.broadcastRootPopupInformation(); }]
         ]);
     }
 
diff --git a/ext/fg/js/popup-proxy.js b/ext/fg/js/popup-proxy.js
index 73148eee..a25f9183 100644
--- a/ext/fg/js/popup-proxy.js
+++ b/ext/fg/js/popup-proxy.js
@@ -21,7 +21,7 @@
  */
 
 class PopupProxy {
-    constructor(id, depth, parentId, parentFrameId, url, applyFrameOffset=async (x, y) => [x, y]) {
+    constructor(id, depth, parentId, parentFrameId, url, applyFrameOffset=null) {
         this._parentId = parentId;
         this._parentFrameId = parentFrameId;
         this._id = id;
@@ -81,7 +81,7 @@ class PopupProxy {
     }
 
     async containsPoint(x, y) {
-        if (this._depth === 0) {
+        if (this._applyFrameOffset !== null) {
             [x, y] = await this._applyFrameOffset(x, y);
         }
         return await this._invokeHostApi('containsPoint', {id: this._id, x, y});
@@ -89,7 +89,7 @@ class PopupProxy {
 
     async showContent(elementRect, writingMode, type=null, details=null) {
         let {x, y, width, height} = elementRect;
-        if (this._depth === 0) {
+        if (this._applyFrameOffset !== null) {
             [x, y] = await this._applyFrameOffset(x, y);
         }
         elementRect = {x, y, width, height};
diff --git a/ext/fg/js/popup.js b/ext/fg/js/popup.js
index 4c979911..47e32963 100644
--- a/ext/fg/js/popup.js
+++ b/ext/fg/js/popup.js
@@ -368,7 +368,6 @@ class Popup {
                 chrome.runtime.onMessage.removeListener(runtimeMessageCallback);
                 callback();
                 resolve();
-                return false;
             }
         };
         chrome.runtime.onMessage.addListener(runtimeMessageCallback);