diff --git a/ui/package.json b/ui/package.json
index 1b3442bb2..a31d89c90 100644
--- a/ui/package.json
+++ b/ui/package.json
@@ -69,8 +69,8 @@
   },
   "jest": {
     "collectCoverageFrom": [
-      "src/**/*.{js,jsx}",
-      "!src/**/*.stories.{js,jsx}"
+      "src/**/*.{js,jsx,tsx}",
+      "!src/**/*.stories.{js,jsx,tsx}"
     ]
   },
   "devDependencies": {
diff --git a/ui/src/AppBoot.js b/ui/src/AppBoot.js
index bf60eb3ab..c43f94869 100644
--- a/ui/src/AppBoot.js
+++ b/ui/src/AppBoot.js
@@ -51,12 +51,17 @@ const ParseDefaultFilters = settingsElement => {
   return defaultFilters;
 };
 
-const ParseUIDefaults = b64data => {
-  const decoded = Buffer.from(b64data, "base64").toString("ascii");
+const ParseUIDefaults = defaultsElement => {
+  if (defaultsElement === null) {
+    return null;
+  }
+  const decoded = Buffer.from(defaultsElement.innerHTML, "base64").toString(
+    "ascii"
+  );
   try {
     return JSON.parse(decoded);
   } catch {
-    return undefined;
+    return null;
   }
 };
 
diff --git a/ui/src/AppBoot.test.js b/ui/src/AppBoot.test.js
index e42a84cc3..51d95a70b 100644
--- a/ui/src/AppBoot.test.js
+++ b/ui/src/AppBoot.test.js
@@ -138,12 +138,17 @@ describe("ParseDefaultFilters()", () => {
 
 describe("ParseUIDefaults()", () => {
   it("parses base64 encoded JSON with defaults", () => {
-    const uiDefaults = ParseUIDefaults(DefaultsBase64);
+    const uiDefaults = ParseUIDefaults({ innerHTML: DefaultsBase64 });
     expect(uiDefaults).toStrictEqual(DefaultsObject);
   });
 
-  it("returns undefined on invalid JSON", () => {
-    const uiDefaults = ParseUIDefaults("e3h4eC9mZgo=");
-    expect(uiDefaults).toBeUndefined();
+  it("returns null on null element", () => {
+    const uiDefaults = ParseUIDefaults(null);
+    expect(uiDefaults).toBeNull();
+  });
+
+  it("returns null on invalid JSON", () => {
+    const uiDefaults = ParseUIDefaults({ innerHTML: "e3h4eC9mZgo=" });
+    expect(uiDefaults).toBeNull();
   });
 });
diff --git a/ui/src/index.test.js b/ui/src/index.test.js
index 330f8c64c..a836de339 100644
--- a/ui/src/index.test.js
+++ b/ui/src/index.test.js
@@ -1,11 +1,45 @@
 import { EmptyAPIResponse } from "__mocks__/Fetch";
 import { DefaultsBase64 } from "__mocks__/Defaults";
 
-it("renders without crashing", () => {
-  jest.spyOn(document, "getElementById").mockImplementationOnce(() => {
-    return {
-      innerHTML: `<div id="defaults">${DefaultsBase64}</div>`
-    };
+const settingsElement = {
+  dataset: {
+    sentryDsn: "",
+    version: "1.2.3",
+    defaultFiltersBase64: "WyJmb289YmFyIiwiYmFyPX5iYXoiXQ=="
+  }
+};
+
+it("renders without crashing with missing defaults div", () => {
+  const root = document.createElement("div");
+  jest.spyOn(global.document, "getElementById").mockImplementation(name => {
+    return name === "settings"
+      ? settingsElement
+      : name === "defaults"
+      ? null
+      : name === "root"
+      ? root
+      : null;
+  });
+  const response = EmptyAPIResponse();
+  response.filters = [];
+  fetch.mockResponse(JSON.stringify(response));
+  const Index = require("./index.tsx");
+  expect(Index).toBeTruthy();
+  expect(root.innerHTML).toMatch(/data-filters="foo=bar bar=~baz"/);
+});
+
+it("renders without crashing with defaults present", () => {
+  const root = document.createElement("div");
+  jest.spyOn(global.document, "getElementById").mockImplementation(name => {
+    return name === "settings"
+      ? settingsElement
+      : name === "defaults"
+      ? {
+          innerHTML: DefaultsBase64
+        }
+      : name === "root"
+      ? root
+      : null;
   });
   const response = EmptyAPIResponse();
   response.filters = [];
diff --git a/ui/src/index.tsx b/ui/src/index.tsx
index 43702d17a..640d99ec2 100644
--- a/ui/src/index.tsx
+++ b/ui/src/index.tsx
@@ -17,25 +17,18 @@ import {
 } from "./AppBoot";
 import { App } from "./App";
 
-let uiDefaults;
-const defaultsElement = document.getElementById("defaults");
-if (defaultsElement !== null) {
-  uiDefaults = ParseUIDefaults(defaultsElement.innerHTML);
-}
-
-const settingsElement = SettingsElement();
-
-SetupSentry(settingsElement);
+SetupSentry(SettingsElement());
 
 // global timer for updating timestamps to human readable offsets
 // this needs to be run before any <Moment/> instance
 // https://www.npmjs.com/package/react-moment#pooled-timer
 Moment.startPooledTimer();
 
-const defaultFilters = ParseDefaultFilters(settingsElement);
-
 // https://wetainment.com/testing-indexjs/
 export default ReactDOM.render(
-  <App defaultFilters={defaultFilters} uiDefaults={uiDefaults} />,
-  document.getElementById("root") || document.createElement("div")
+  <App
+    defaultFilters={ParseDefaultFilters(SettingsElement())}
+    uiDefaults={ParseUIDefaults(document.getElementById("defaults"))}
+  />,
+  document.getElementById("root")
 );