--- a/browser/extensions/formautofill/test/browser/browser.ini
+++ b/browser/extensions/formautofill/test/browser/browser.ini
@@ -1,14 +1,16 @@
 [DEFAULT]
 head = head.js
 
 support-files =
   ../fixtures/autocomplete_basic.html
 
 [browser_autocomplete_footer.js]
+[browser_autocomplete_marked_back_forward.js]
+[browser_autocomplete_marked_detached_tab.js]
 [browser_check_installed.js]
 [browser_editProfileDialog.js]
 [browser_first_time_use_doorhanger.js]
 [browser_privacyPreferences.js]
 [browser_manageProfilesDialog.js]
 [browser_submission_in_private_mode.js]
 [browser_update_doorhanger.js]

new file mode 100644
--- /dev/null
+++ b/browser/extensions/formautofill/test/browser/browser_autocomplete_marked_back_forward.js
@@ -0,0 +1,61 @@
+/**
+ * Test that autofill autocomplete works after back/forward navigation
+ */
+
+"use strict";
+
+const URL = BASE_URL + "autocomplete_basic.html";
+
+function checkPopup(autoCompletePopup) {
+  let first = autoCompletePopup.view.results[0];
+  const {primary, secondary} = JSON.parse(first.label);
+  ok(primary.startsWith(TEST_ADDRESS_1["street-address"].split("\n")[0]),
+     "Check primary label is street address");
+  is(secondary, TEST_ADDRESS_1["address-level2"], "Check secondary label is address-level2");
+}
+
+add_task(async function setup_storage() {
+  await saveAddress(TEST_ADDRESS_1);
+  await saveAddress(TEST_ADDRESS_2);
+  await saveAddress(TEST_ADDRESS_3);
+});
+
+add_task(async function test_back_forward() {
+  await BrowserTestUtils.withNewTab({gBrowser, url: URL}, async function(browser) {
+    const {autoCompletePopup} = browser;
+
+    // Check the page after the initial load
+    await openPopupOn(browser, "#street-address");
+    checkPopup(autoCompletePopup);
+
+    // Now navigate forward and make sure autofill autocomplete results are still attached
+    let loadPromise = BrowserTestUtils.browserLoaded(browser);
+    await BrowserTestUtils.loadURI(browser, `${URL}?load=2`);
+    await loadPromise;
+
+    // Check the second page
+    await openPopupOn(browser, "#street-address");
+    checkPopup(autoCompletePopup);
+
+    // Check after hitting back to the first page
+    let stoppedPromise = BrowserTestUtils.browserStopped(browser);
+    browser.goBack();
+    await stoppedPromise;
+    await openPopupOn(browser, "#street-address");
+    checkPopup(autoCompletePopup);
+
+    // Check after hitting forward to the second page
+    stoppedPromise = BrowserTestUtils.browserStopped(browser);
+    browser.goForward();
+    await stoppedPromise;
+    await openPopupOn(browser, "#street-address");
+    checkPopup(autoCompletePopup);
+
+    // Ensure the popup is closed before entering the next test.
+    await ContentTask.spawn(browser, {}, async function() {
+      content.document.getElementById("street-address").blur();
+    });
+    await BrowserTestUtils.waitForCondition(() => !autoCompletePopup.popupOpen,
+                                            "popup should have closed");
+  });
+});

new file mode 100644
--- /dev/null
+++ b/browser/extensions/formautofill/test/browser/browser_autocomplete_marked_detached_tab.js
@@ -0,0 +1,54 @@
+/**
+ * Test that autofill autocomplete works after detaching a tab
+ */
+
+"use strict";
+
+const URL = BASE_URL + "autocomplete_basic.html";
+
+function checkPopup(autoCompletePopup) {
+  let first = autoCompletePopup.view.results[0];
+  const {primary, secondary} = JSON.parse(first.label);
+  ok(primary.startsWith(TEST_ADDRESS_1["street-address"].split("\n")[0]),
+     "Check primary label is street address");
+  is(secondary, TEST_ADDRESS_1["address-level2"], "Check secondary label is address-level2");
+}
+
+add_task(async function setup_storage() {
+  await saveAddress(TEST_ADDRESS_1);
+  await saveAddress(TEST_ADDRESS_2);
+  await saveAddress(TEST_ADDRESS_3);
+});
+
+add_task(async function test_detach_tab_marked() {
+  await BrowserTestUtils.withNewTab({gBrowser, url: URL}, async function(browser) {
+    const {autoCompletePopup} = browser;
+
+    // Check the page after the initial load
+    await openPopupOn(browser, "#street-address");
+    checkPopup(autoCompletePopup);
+
+    // Detach the tab to a new window
+    let newWin = gBrowser.replaceTabWithWindow(gBrowser.getTabForBrowser(browser));
+    await TestUtils.topicObserved("browser-delayed-startup-finished", subject => {
+      return subject == newWin;
+    });
+
+    info("tab was detached");
+    let newBrowser = newWin.gBrowser.selectedBrowser;
+    ok(newBrowser, "Found new <browser>");
+    let newAutoCompletePopup = newBrowser.autoCompletePopup;
+    ok(newAutoCompletePopup, "Found new autocomplete popup");
+
+    await openPopupOn(newBrowser, "#street-address");
+    checkPopup(newAutoCompletePopup);
+
+    // Ensure the popup is closed before entering the next test.
+    await ContentTask.spawn(newBrowser, {}, async function() {
+      content.document.getElementById("street-address").blur();
+    });
+    await BrowserTestUtils.waitForCondition(() => !newAutoCompletePopup.popupOpen,
+                                           "popup should have closed");
+    await BrowserTestUtils.closeWindow(newWin);
+  });
+});

--- a/browser/extensions/formautofill/test/browser/head.js
+++ b/browser/extensions/formautofill/test/browser/head.js
@@ -39,27 +39,29 @@ const SECONDARY_BUTTON_INDEX = 1;
 async function sleep(ms = 500) {
   await new Promise(resolve => setTimeout(resolve, ms));
 }
 
 async function expectPopupOpen(browser) {
   const {autoCompletePopup, autoCompletePopup: {richlistbox: itemsBox}} = browser;
   const listItemElems = itemsBox.querySelectorAll(".autocomplete-richlistitem");
 
-  await BrowserTestUtils.waitForCondition(() => autoCompletePopup.popupOpen);
+  await BrowserTestUtils.waitForCondition(() => autoCompletePopup.popupOpen,
+                                         "popup should be open");
   await BrowserTestUtils.waitForCondition(() => {
     return [...listItemElems].every(item => {
       return (item.getAttribute("originaltype") == "autofill-profile" ||
              item.getAttribute("originaltype") == "autofill-footer") &&
              item.hasAttribute("formautofillattached");
     });
-  });
+  }, "The popup should be a form autofill one");
 }
 
 async function openPopupOn(browser, selector) {
+  await SimpleTest.promiseFocus(browser);
   /* eslint no-shadow: ["error", { "allow": ["selector"] }] */
   await ContentTask.spawn(browser, {selector}, async function({selector}) {
     content.document.querySelector(selector).focus();
   });
   await sleep(2000);
   await BrowserTestUtils.synthesizeKey("VK_DOWN", {}, browser);
   await expectPopupOpen(browser);
 }