diff --git a/apps/browser/src/autofill/overlay/pages/button/autofill-overlay-button.spec.ts b/apps/browser/src/autofill/overlay/pages/button/autofill-overlay-button.spec.ts
index d19a75c04a2..4a1cf47d1ed 100644
--- a/apps/browser/src/autofill/overlay/pages/button/autofill-overlay-button.spec.ts
+++ b/apps/browser/src/autofill/overlay/pages/button/autofill-overlay-button.spec.ts
@@ -1,7 +1,9 @@
+import { mock } from "jest-mock-extended";
+
 import { AuthenticationStatus } from "@bitwarden/common/auth/enums/authentication-status";
 
 import { createInitAutofillOverlayButtonMessageMock } from "../../../spec/autofill-mocks";
-import { postWindowMessage } from "../../../spec/testing-utils";
+import { flushPromises, postWindowMessage } from "../../../spec/testing-utils";
 
 import AutofillOverlayButton from "./autofill-overlay-button";
 
@@ -9,13 +11,20 @@ describe("AutofillOverlayButton", () => {
   globalThis.customElements.define("autofill-overlay-button", AutofillOverlayButton);
 
   let autofillOverlayButton: AutofillOverlayButton;
+  let messageConnectorIframe: HTMLIFrameElement;
+  const portKey: string = "overlayButtonPortKey";
 
   beforeEach(() => {
     document.body.innerHTML = `<autofill-overlay-button></autofill-overlay-button>`;
     autofillOverlayButton = document.querySelector("autofill-overlay-button");
     autofillOverlayButton["messageOrigin"] = "https://localhost/";
+    messageConnectorIframe = mock<HTMLIFrameElement>({
+      contentWindow: { postMessage: jest.fn() },
+    });
+    autofillOverlayButton["messageConnectorIframe"] = messageConnectorIframe;
+    jest.spyOn(autofillOverlayButton as any, "initMessageConnector").mockResolvedValue(undefined);
     jest.spyOn(globalThis.document, "createElement");
-    jest.spyOn(globalThis.parent, "postMessage");
+    jest.spyOn(messageConnectorIframe.contentWindow, "postMessage");
   });
 
   afterEach(() => {
@@ -23,10 +32,14 @@ describe("AutofillOverlayButton", () => {
   });
 
   describe("initAutofillOverlayButton", () => {
-    it("creates the button element with the locked icon when the user's auth status is not Unlocked", () => {
+    it("creates the button element with the locked icon when the user's auth status is not Unlocked", async () => {
       postWindowMessage(
-        createInitAutofillOverlayButtonMessageMock({ authStatus: AuthenticationStatus.Locked }),
+        createInitAutofillOverlayButtonMessageMock({
+          authStatus: AuthenticationStatus.Locked,
+          portKey,
+        }),
       );
+      await flushPromises();
 
       expect(autofillOverlayButton["buttonElement"]).toMatchSnapshot();
       expect(autofillOverlayButton["buttonElement"].querySelector("svg")).toBe(
@@ -34,8 +47,9 @@ describe("AutofillOverlayButton", () => {
       );
     });
 
-    it("creates the button element with the normal icon when the user's auth status is Unlocked ", () => {
-      postWindowMessage(createInitAutofillOverlayButtonMessageMock());
+    it("creates the button element with the normal icon when the user's auth status is Unlocked ", async () => {
+      postWindowMessage(createInitAutofillOverlayButtonMessageMock({ portKey }));
+      await flushPromises();
 
       expect(autofillOverlayButton["buttonElement"]).toMatchSnapshot();
       expect(autofillOverlayButton["buttonElement"].querySelector("svg")).toBe(
@@ -43,55 +57,60 @@ describe("AutofillOverlayButton", () => {
       );
     });
 
-    it("posts a message to the background indicating that the icon was clicked", () => {
-      postWindowMessage(createInitAutofillOverlayButtonMessageMock());
+    it("posts a message to the background indicating that the icon was clicked", async () => {
+      postWindowMessage(createInitAutofillOverlayButtonMessageMock({ portKey }));
+      await flushPromises();
+
       autofillOverlayButton["buttonElement"].click();
 
-      expect(globalThis.parent.postMessage).toHaveBeenCalledWith(
-        { command: "overlayButtonClicked" },
-        "https://localhost/",
+      expect(messageConnectorIframe.contentWindow.postMessage).toHaveBeenCalledWith(
+        { command: "overlayButtonClicked", portKey },
+        "*",
       );
     });
   });
 
   describe("global event listeners", () => {
     beforeEach(() => {
-      postWindowMessage(createInitAutofillOverlayButtonMessageMock());
+      postWindowMessage(createInitAutofillOverlayButtonMessageMock({ portKey }));
     });
 
-    it("does not post a message to close the autofill overlay if the element is focused during the focus check", () => {
+    it("does not post a message to close the autofill overlay if the element is focused during the focus check", async () => {
       jest.spyOn(globalThis.document, "hasFocus").mockReturnValue(true);
 
       postWindowMessage({ command: "checkAutofillOverlayButtonFocused" });
+      await flushPromises();
 
-      expect(globalThis.parent.postMessage).not.toHaveBeenCalledWith({
+      expect(messageConnectorIframe.contentWindow.postMessage).not.toHaveBeenCalledWith({
         command: "closeAutofillOverlay",
       });
     });
 
-    it("posts a message to close the autofill overlay if the element is not focused during the focus check", () => {
+    it("posts a message to close the autofill overlay if the element is not focused during the focus check", async () => {
       jest.spyOn(globalThis.document, "hasFocus").mockReturnValue(false);
 
       postWindowMessage({ command: "checkAutofillOverlayButtonFocused" });
+      await flushPromises();
 
-      expect(globalThis.parent.postMessage).toHaveBeenCalledWith(
-        { command: "closeAutofillOverlay" },
-        "https://localhost/",
+      expect(messageConnectorIframe.contentWindow.postMessage).toHaveBeenCalledWith(
+        { command: "closeAutofillOverlay", portKey },
+        "*",
       );
     });
 
-    it("updates the user's auth status", () => {
+    it("updates the user's auth status", async () => {
       autofillOverlayButton["authStatus"] = AuthenticationStatus.Locked;
 
       postWindowMessage({
         command: "updateAutofillOverlayButtonAuthStatus",
         authStatus: AuthenticationStatus.Unlocked,
       });
+      await flushPromises();
 
       expect(autofillOverlayButton["authStatus"]).toBe(AuthenticationStatus.Unlocked);
     });
 
-    it("updates the page color scheme meta tag", () => {
+    it("updates the page color scheme meta tag", async () => {
       const colorSchemeMetaTag = globalThis.document.createElement("meta");
       colorSchemeMetaTag.setAttribute("name", "color-scheme");
       colorSchemeMetaTag.setAttribute("content", "light");
@@ -101,6 +120,7 @@ describe("AutofillOverlayButton", () => {
         command: "updateOverlayPageColorScheme",
         colorScheme: "dark",
       });
+      await flushPromises();
 
       expect(colorSchemeMetaTag.getAttribute("content")).toBe("dark");
     });
diff --git a/apps/browser/src/autofill/overlay/pages/list/autofill-overlay-list.spec.ts b/apps/browser/src/autofill/overlay/pages/list/autofill-overlay-list.spec.ts
index 3dc8613c2aa..ee4c3c73bfd 100644
--- a/apps/browser/src/autofill/overlay/pages/list/autofill-overlay-list.spec.ts
+++ b/apps/browser/src/autofill/overlay/pages/list/autofill-overlay-list.spec.ts
@@ -24,14 +24,11 @@ describe("AutofillOverlayList", () => {
     autofillOverlayList = document.querySelector("autofill-overlay-list");
     autofillOverlayList["messageOrigin"] = "https://localhost/";
     messageConnectorIframe = mock<HTMLIFrameElement>({
-      contentWindow: {
-        postMessage: jest.fn(),
-      },
+      contentWindow: { postMessage: jest.fn() },
     });
     autofillOverlayList["messageConnectorIframe"] = messageConnectorIframe;
     jest.spyOn(autofillOverlayList as any, "initMessageConnector").mockResolvedValue(undefined);
     jest.spyOn(globalThis.document, "createElement");
-    jest.spyOn(globalThis.parent, "postMessage");
   });
 
   afterEach(() => {