diff --git a/manifest.json b/manifest.json
index dbba8b7..69c08f7 100644
--- a/manifest.json
+++ b/manifest.json
@@ -1,7 +1,7 @@
 {
   "manifest_version": 2,
   "name": "graytabby",
-  "version": "19.12.11",
+  "version": "20.05.17",
   "icons": {
     "128": "assets/img/blobbycat/browseraction128.png"
   },
diff --git a/src/lib/utils.ts b/src/lib/utils.ts
index a8af40f..8ca9d79 100644
--- a/src/lib/utils.ts
+++ b/src/lib/utils.ts
@@ -7,6 +7,14 @@ export function fieldKeeper<T, K extends keyof T>(obj: T, ...keys: K[]): Pick<T,
   return copy;
 }
 
+export function dictOf(...args: any[]): { [key: string]: any } {
+  const ret: { [key: string]: any } = {};
+  for (let i = 0; i < args.length; i += 2) {
+    ret[<string>args[i]] = args[i + 1];
+  }
+  return ret;
+}
+
 export async function save(key: string, value: any): Promise<void> {
   const record: any = {};
   record[key] = value;
diff --git a/tests/archive.test.ts b/tests/archive.test.ts
index 66c65b6..196a1fe 100644
--- a/tests/archive.test.ts
+++ b/tests/archive.test.ts
@@ -1,12 +1,12 @@
 import { expect } from 'chai';
-import * as mockBrowser from 'sinon-chrome';
 import { archivePlan } from '../src/bg/archive';
 import { Broker, BrokerConsumer } from '../src/lib/brokers';
 import { ARCHIVAL, DOCUMENT } from '../src/lib/globals';
 import { dateFromKey, INDEX_V2_KEY } from '../src/app/tabs';
-import { assertElement, testTab, stubGlobals, unstubGlobals } from './utils';
+import { assertElement, testTab, stubGlobals, unstubGlobals, mockedBrowser } from './utils';
 import { BrowserTab } from '../src/lib/types';
 import { graytabby } from '../src/app/ui';
+import { dictOf } from '../src/lib/utils';
 
 describe('archive operation', function() {
   beforeEach(async function() {
@@ -32,9 +32,9 @@ describe('archive operation', function() {
     consumer([testTab({ url: 'http://example.com' })], {}, () => null);
     const group = assertElement('#groups > div', DOCUMENT.get());
 
-    mockBrowser.storage.local.get
-      .withArgs(INDEX_V2_KEY)
-      .returns(new Promise(() => [dateFromKey(group.id)]));
+    mockedBrowser()
+      .storage.local.get.withArgs(INDEX_V2_KEY)
+      .returns(Promise.resolve(dictOf(INDEX_V2_KEY, [dateFromKey(group.id)])));
     const a = <HTMLAnchorElement>assertElement('a', group);
     a.click();
   });
diff --git a/tests/tabs.test.ts b/tests/tabs.test.ts
new file mode 100644
index 0000000..a279a1c
--- /dev/null
+++ b/tests/tabs.test.ts
@@ -0,0 +1,52 @@
+import { expect } from 'chai';
+import { GrayTabGroup, INDEX_V1_KEY, loadAllTabGroups } from '../src/app/tabs';
+import { dictOf } from '../src/lib/utils';
+import { mockedBrowser, stubGlobals, unstubGlobals } from './utils';
+
+describe('tabs', function() {
+  beforeEach(async function() {
+    await stubGlobals();
+  });
+
+  afterEach(function() {
+    unstubGlobals();
+  });
+
+  it('should load old string format', async function() {
+    const oldGroups: GrayTabGroup[] = [
+      {
+        tabs: [
+          {
+            url: '1',
+            title: 'one',
+            key: 0,
+          },
+          {
+            url: '2',
+            title: 'two',
+            key: 1,
+          },
+        ],
+        date: 1589760256, // May 17 2020 in Linux Timestamp.
+      },
+      {
+        tabs: [
+          {
+            url: '3',
+            title: 'three',
+            key: 0,
+          },
+        ],
+        date: 1589760257,
+      },
+    ];
+    mockedBrowser()
+      .storage.local.get.withArgs(INDEX_V1_KEY)
+      .returns(Promise.resolve(dictOf(INDEX_V1_KEY, JSON.stringify(oldGroups))));
+    const groups = await loadAllTabGroups();
+    for (const oldGroup of oldGroups) {
+      oldGroup.date *= 1000; // Seconds to millis conversion.
+    }
+    expect(groups).to.deep.equal(oldGroups);
+  });
+});
diff --git a/tests/utils.ts b/tests/utils.ts
index 4d61536..3862498 100644
--- a/tests/utils.ts
+++ b/tests/utils.ts
@@ -2,10 +2,10 @@ import { expect } from 'chai';
 import { JSDOM } from 'jsdom';
 import * as mockBrowser from 'sinon-chrome';
 import { INDEX_V1_KEY, INDEX_V2_KEY } from '../src/app/tabs';
-import { graytabby } from '../src/app/ui';
 import { BROWSER, DOCUMENT } from '../src/lib/globals';
 import { OPTIONS_KEY } from '../src/lib/options';
 import { BrowserTab } from '../src/lib/types';
+import SinonChrome from 'sinon-chrome';
 
 export async function stubGlobals(): Promise<void> {
   BROWSER.set(<any>mockBrowser);
@@ -22,6 +22,10 @@ export function unstubGlobals(): void {
   DOCUMENT.set(null);
 }
 
+export function mockedBrowser(): typeof SinonChrome {
+  return <typeof SinonChrome>(<any>BROWSER.get());
+}
+
 export function testTab(args: Partial<BrowserTab>): BrowserTab {
   return {
     index: 1,