diff --git a/ext/fg/js/popup-proxy-host.js b/ext/fg/js/popup-proxy-host.js
index 4dc79943..487dda90 100644
--- a/ext/fg/js/popup-proxy-host.js
+++ b/ext/fg/js/popup-proxy-host.js
@@ -19,6 +19,7 @@
 /* global
  * FrontendApiReceiver
  * Popup
+ * apiForward
  * apiFrameInformationGet
  */
 
@@ -48,6 +49,12 @@ class PopupProxyHost {
             ['clearAutoPlayTimer', this._onApiClearAutoPlayTimer.bind(this)],
             ['setContentScale', this._onApiSetContentScale.bind(this)]
         ]));
+
+        this._windowMessageHandlers = new Map([
+            ['getIframeOffset', ({offset, uniqueId}, e) => { return this._onGetIframeOffset(offset, uniqueId, e); }]
+        ]);
+
+        window.addEventListener('message', this.onMessage.bind(this), false);
     }
 
     getOrCreatePopup(id=null, parentId=null, depth=null) {
@@ -95,7 +102,7 @@ class PopupProxyHost {
         return popup;
     }
 
-    // Message handlers
+    // API message handlers
 
     async _onApiGetOrCreatePopup({id, parentId}) {
         const popup = this.getOrCreatePopup(id, parentId);
@@ -152,6 +159,30 @@ class PopupProxyHost {
         return popup.setContentScale(scale);
     }
 
+    // Window message handlers
+
+    onMessage(e) {
+        const {action, params} = e.data;
+        const handler = this._windowMessageHandlers.get(action);
+        if (typeof handler !== 'function') { return; }
+        handler(params, e);
+    }
+
+    _onGetIframeOffset(offset, uniqueId, e) {
+        let sourceIframe = null;
+        for (const iframe of document.querySelectorAll('iframe:not(.yomichan-float)')) {
+            if (iframe.contentWindow !== e.source) { continue; }
+            sourceIframe = iframe;
+            break;
+        }
+        if (sourceIframe === null) { return; }
+
+        const [forwardedX, forwardedY] = offset;
+        const {x, y} = sourceIframe.getBoundingClientRect();
+        offset = [forwardedX + x, forwardedY + y];
+        apiForward('iframeOffset', {offset, uniqueId});
+    }
+
     // Private functions
 
     _getPopup(id) {
diff --git a/ext/fg/js/popup-proxy.js b/ext/fg/js/popup-proxy.js
index 997b1317..c1ee76ce 100644
--- a/ext/fg/js/popup-proxy.js
+++ b/ext/fg/js/popup-proxy.js
@@ -29,6 +29,12 @@ class PopupProxy {
         this._depth = depth;
         this._url = url;
         this._apiSender = new FrontendApiSender();
+
+        this._windowMessageHandlers = new Map([
+            ['getIframeOffset', ({offset, uniqueId}, e) => { return this._onGetIframeOffset(offset, uniqueId, e); }]
+        ]);
+
+        window.addEventListener('message', this.onMessage.bind(this), false);
     }
 
     // Public properties
@@ -83,12 +89,19 @@ class PopupProxy {
         if (this._id === null) {
             return false;
         }
+        if (this._depth === 0) {
+            [x, y] = await PopupProxy._convertIframePointToRootPagePoint(x, y);
+        }
         return await this._invokeHostApi('containsPoint', {id: this._id, x, y});
     }
 
     async showContent(elementRect, writingMode, type=null, details=null) {
         const id = await this._getPopupId();
-        elementRect = PopupProxy._convertDOMRectToJson(elementRect);
+        let {x, y, width, height} = PopupProxy._convertDOMRectToJson(elementRect);
+        if (this._depth === 0) {
+            [x, y] = await PopupProxy._convertIframePointToRootPagePoint(x, y);
+            elementRect = {x, y, width, height};
+        }
         return await this._invokeHostApi('showContent', {id, elementRect, writingMode, type, details});
     }
 
@@ -109,6 +122,31 @@ class PopupProxy {
         this._invokeHostApi('setContentScale', {id, scale});
     }
 
+    // Window message handlers
+
+    onMessage(e) {
+        const {action, params} = e.data;
+        const handler = this._windowMessageHandlers.get(action);
+        if (typeof handler !== 'function') { return; }
+        handler(params, e);
+    }
+
+    _onGetIframeOffset(offset, uniqueId, e) {
+        let sourceIframe = null;
+        for (const iframe of document.querySelectorAll('iframe:not(.yomichan-float)')) {
+            if (iframe.contentWindow !== e.source) { continue; }
+            sourceIframe = iframe;
+            break;
+        }
+        if (sourceIframe === null) { return; }
+
+        const [forwardedX, forwardedY] = offset;
+        const {x, y} = sourceIframe.getBoundingClientRect();
+        offset = [forwardedX + x, forwardedY + y];
+        window.parent.postMessage({action: 'getIframeOffset', params: {offset, uniqueId}}, '*');
+    }
+
+
     // Private
 
     _getPopupId() {
@@ -131,6 +169,35 @@ class PopupProxy {
         return this._apiSender.invoke(action, params, `popup-proxy-host#${this._parentFrameId}`);
     }
 
+    static async _convertIframePointToRootPagePoint(x, y) {
+        const uniqueId = yomichan.generateId(16);
+
+        let frameOffsetResolve = null;
+        const frameOffsetPromise = new Promise((resolve) => (frameOffsetResolve = resolve));
+
+        const runtimeMessageCallback = ({action, params}, sender, callback) => {
+            if (action === 'iframeOffset' && isObject(params) && params.uniqueId === uniqueId) {
+                chrome.runtime.onMessage.removeListener(runtimeMessageCallback);
+                callback();
+                frameOffsetResolve(params);
+                return false;
+            }
+        };
+        chrome.runtime.onMessage.addListener(runtimeMessageCallback);
+
+        window.parent.postMessage({
+            action: 'getIframeOffset',
+            params: {
+                uniqueId,
+                offset: [x, y]
+            }
+        }, '*');
+
+        const {offset} = await frameOffsetPromise;
+
+        return offset;
+    }
+
     static _convertDOMRectToJson(domRect) {
         return {
             x: domRect.x,