diff --git a/src/GleapAdminManager.js b/src/GleapAdminManager.js
index 5e548258..a85674cd 100644
--- a/src/GleapAdminManager.js
+++ b/src/GleapAdminManager.js
@@ -1,6 +1,7 @@
 import { loadIcon } from './UI';
 import GleapAdminHelper from './GleapAdminHelper';
 import Gleap, { GleapModalManager, GleapProductTours, GleapBannerManager } from './Gleap';
+import { isGleapAdminOrigin, resolveGleapAdminOrigin } from './GleapAdminOrigins';
 
 export default class GleapAdminManager {
   libraryInstance = null;
@@ -14,6 +15,8 @@ export default class GleapAdminManager {
   adminHelper = null;
   status = 'navigate';
   initialized = false;
+  // Dashboard origin that opened the admin session (set from the validated `load` message).
+  adminOrigin = null;
 
   // GleapAdminManager singleton
   static instance;
@@ -105,7 +108,7 @@ export default class GleapAdminManager {
 
     // Add window message listener.
     window.addEventListener('message', (event) => {
-      if (event.origin !== 'https://app.gleap.io') {
+      if (!isGleapAdminOrigin(event.origin)) {
         return;
       }
 
@@ -114,6 +117,9 @@ export default class GleapAdminManager {
 
         if (data.type === 'admin') {
           if (data.name === 'load') {
+            if (!self.adminOrigin) {
+              self.adminOrigin = resolveGleapAdminOrigin(event.origin);
+            }
             self.configData = data.data;
             self.initAdminHelper();
           }
@@ -230,7 +236,9 @@ export default class GleapAdminManager {
             ...data,
             type: 'admin',
           }),
-          '*'
+          // `init` goes out before the dashboard origin is known; everything after `load` is
+          // only delivered to the dashboard that opened the session.
+          this.adminOrigin || '*'
         );
       }
     } catch (e) {}
@@ -244,7 +252,7 @@ export default class GleapAdminManager {
             ...data,
             type: 'tourbuilder',
           }),
-          '*'
+          resolveGleapAdminOrigin(this.adminOrigin)
         );
       }
     } catch (e) {}
@@ -309,7 +317,7 @@ export default class GleapAdminManager {
     // Inject widget HTML.
     var elem = document.createElement('div');
     elem.className = 'gleap-admin-frame-container';
-    elem.innerHTML = `<iframe src="https://app.gleap.io/${
+    elem.innerHTML = `<iframe src="${resolveGleapAdminOrigin(this.adminOrigin)}/${
       this?.configData?.type === 'tooltips' ? 'tooltipbuilder' : 'producttourbuilder'
     }" class="gleap-admin-frame" scrolling="no" title="Gleap Admin Window" allow="autoplay; encrypted-media; fullscreen;" frameborder="0"></iframe>`;
     document.body.appendChild(elem);
diff --git a/src/GleapAdminOrigins.js b/src/GleapAdminOrigins.js
new file mode 100644
index 00000000..13a08215
--- /dev/null
+++ b/src/GleapAdminOrigins.js
@@ -0,0 +1,24 @@
+/**
+ * Dashboard origins that may drive the product tour / tooltip builder (admin mode).
+ *
+ * The dashboard moved from app.gleap.io to app.gleap.ai; both serve the same app.
+ * Exact string match only: never a suffix or wildcard check, which `evilgleap.ai`
+ * or `app.gleap.ai.evil.com` could pass.
+ */
+export const GLEAP_ADMIN_ORIGINS = Object.freeze(['https://app.gleap.ai', 'https://app.gleap.io']);
+
+export const GLEAP_DEFAULT_ADMIN_ORIGIN = 'https://app.gleap.ai';
+
+/**
+ * @param {*} origin - a MessageEvent origin.
+ * @returns {boolean} true only for an exact allowlisted dashboard origin.
+ */
+export const isGleapAdminOrigin = (origin) => typeof origin === 'string' && GLEAP_ADMIN_ORIGINS.indexOf(origin) !== -1;
+
+/**
+ * The origin the builder iframe is loaded from: the dashboard origin that opened the
+ * admin session, falling back to the default dashboard.
+ * @param {*} origin - the origin of the validated opener message.
+ * @returns {string}
+ */
+export const resolveGleapAdminOrigin = (origin) => (isGleapAdminOrigin(origin) ? origin : GLEAP_DEFAULT_ADMIN_ORIGIN);
diff --git a/src/GleapAdminOrigins.test.js b/src/GleapAdminOrigins.test.js
new file mode 100644
index 00000000..323710db
--- /dev/null
+++ b/src/GleapAdminOrigins.test.js
@@ -0,0 +1,109 @@
+/**
+ * @jest-environment jsdom
+ */
+import GleapAdminManager from './GleapAdminManager';
+import {
+  GLEAP_ADMIN_ORIGINS,
+  GLEAP_DEFAULT_ADMIN_ORIGIN,
+  isGleapAdminOrigin,
+  resolveGleapAdminOrigin,
+} from './GleapAdminOrigins';
+
+const LOOKALIKES = [
+  'https://app.gleap.ai.evil.com',
+  'https://app.gleap.io.evil.com',
+  'https://evilgleap.ai',
+  'https://evilgleap.io',
+  'https://evil.app.gleap.ai',
+  'https://gleap.ai',
+  'https://app.gleap.ai:8443',
+  'http://app.gleap.ai',
+  'http://app.gleap.io',
+  'https://APP.GLEAP.AI',
+  'https://app.gleap.ai/',
+  'null',
+  '',
+  undefined,
+  null,
+  ['https://app.gleap.ai'],
+];
+
+describe('admin origin allowlist', () => {
+  it('is exactly the two dashboard origins', () => {
+    expect([...GLEAP_ADMIN_ORIGINS].sort()).toEqual(['https://app.gleap.ai', 'https://app.gleap.io']);
+    expect(GLEAP_DEFAULT_ADMIN_ORIGIN).toBe('https://app.gleap.ai');
+  });
+
+  it('accepts both dashboard hosts', () => {
+    expect(isGleapAdminOrigin('https://app.gleap.ai')).toBe(true);
+    expect(isGleapAdminOrigin('https://app.gleap.io')).toBe(true);
+  });
+
+  it.each(LOOKALIKES)('rejects %p', (origin) => {
+    expect(isGleapAdminOrigin(origin)).toBe(false);
+    expect(resolveGleapAdminOrigin(origin)).toBe(GLEAP_DEFAULT_ADMIN_ORIGIN);
+  });
+
+  it('keeps the opener origin for the builder', () => {
+    expect(resolveGleapAdminOrigin('https://app.gleap.io')).toBe('https://app.gleap.io');
+    expect(resolveGleapAdminOrigin('https://app.gleap.ai')).toBe('https://app.gleap.ai');
+  });
+});
+
+describe('GleapAdminManager message origin', () => {
+  let manager;
+  let listeners;
+
+  const post = (origin, payload) =>
+    window.dispatchEvent(new MessageEvent('message', { origin, data: JSON.stringify(payload) }));
+
+  const load = (origin, type = 'tours') => post(origin, { type: 'admin', name: 'load', data: { type } });
+
+  beforeEach(() => {
+    document.body.innerHTML = '';
+    GleapAdminManager.instance = undefined;
+    manager = GleapAdminManager.getInstance();
+    // Keep the admin UI side effects out of the origin check.
+    manager.initAdminHelper = jest.fn(() => manager.injectFrame());
+    manager.startPageListener = jest.fn();
+    listeners = [];
+    const add = window.addEventListener.bind(window);
+    jest.spyOn(window, 'addEventListener').mockImplementation((type, fn, opts) => {
+      if (type === 'message') listeners.push(fn);
+      return add(type, fn, opts);
+    });
+    manager.start();
+  });
+
+  afterEach(() => {
+    listeners.forEach((fn) => window.removeEventListener('message', fn));
+    jest.restoreAllMocks();
+  });
+
+  it.each(['https://app.gleap.ai.evil.com', 'https://evilgleap.ai', 'https://example.com'])(
+    'ignores a load from %s',
+    (origin) => {
+      load(origin);
+      expect(manager.initAdminHelper).not.toHaveBeenCalled();
+      expect(manager.adminOrigin).toBeNull();
+      expect(document.querySelector('.gleap-admin-frame')).toBeNull();
+    }
+  );
+
+  it.each([
+    ['https://app.gleap.ai', 'tours', 'https://app.gleap.ai/producttourbuilder'],
+    ['https://app.gleap.io', 'tooltips', 'https://app.gleap.io/tooltipbuilder'],
+  ])('loads the builder from the opener origin %s', (origin, type, src) => {
+    load(origin, type);
+    expect(manager.initAdminHelper).toHaveBeenCalledTimes(1);
+    expect(manager.adminOrigin).toBe(origin);
+    expect(document.querySelector('.gleap-admin-frame').getAttribute('src')).toBe(src);
+  });
+
+  it('defaults the builder to app.gleap.ai', () => {
+    manager.injectFrame();
+    expect(document.querySelector('.gleap-admin-frame').getAttribute('src')).toBe(
+      'https://app.gleap.ai/producttourbuilder'
+    );
+  });
+});