diff --git a/toolkit/components/extensions/test/mochitest/mochitest.ini b/toolkit/components/extensions/test/mochitest/mochitest.ini
index 8b143ddbc7b8..624dd41d9bbc 100644
--- a/toolkit/components/extensions/test/mochitest/mochitest.ini
+++ b/toolkit/components/extensions/test/mochitest/mochitest.ini
@@ -85,6 +85,7 @@ skip-if = os == 'android' # Android does not currently support tabs.
 [test_ext_background_teardown.html]
 [test_ext_tab_teardown.html]
 skip-if = (os == 'android') # Android does not support tabs API. Bug 1260250
+[test_ext_unload_frame.html]
 [test_ext_i18n.html]
 skip-if = (os == 'android') # Bug 1258975 on android.
 [test_ext_web_accessible_resources.html]
diff --git a/toolkit/components/extensions/test/mochitest/test_ext_unload_frame.html b/toolkit/components/extensions/test/mochitest/test_ext_unload_frame.html
new file mode 100644
index 000000000000..1ae6262b3d48
--- /dev/null
+++ b/toolkit/components/extensions/test/mochitest/test_ext_unload_frame.html
@@ -0,0 +1,158 @@
+<!DOCTYPE HTML>
+<html>
+<head>
+  <title>WebExtensions test</title>
+  <script type="text/javascript" src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/SpawnTask.js"></script>
+  <script type="text/javascript" src="/tests/SimpleTest/ExtensionTestUtils.js"></script>
+  <script type="text/javascript" src="head.js"></script>
+  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css">
+</head>
+<body>
+
+<script>
+"use strict";
+
+/* globals delayedNotifyPass */ // Available in the background page of the test extensions.
+
+// Background and content script for testSendMessage_*
+function sendMessage_background() {
+  browser.runtime.onMessage.addListener((msg, sender, sendResponse) => {
+    browser.test.assertEq("from frame", msg, "Expected message from frame");
+    sendResponse("msg from back");  // Should not throw or anything like that.
+    delayedNotifyPass("Received sendMessage from closing frame");
+  });
+}
+function sendMessage_contentScript(testType) {
+  browser.runtime.sendMessage("from frame", reply => {
+    // The frame has been removed, so we should not get this callback!
+    browser.test.fail(`Unexpected reply: ${reply}`);
+  });
+  if (testType == "frame") {
+    frameElement.remove();
+  } else {
+    window.close();
+  }
+}
+
+// Background and content script for testConnect_*
+function connect_background() {
+  browser.runtime.onConnect.addListener(port => {
+    browser.test.assertEq("port from frame", port.name);
+
+    let disconnected = false;
+    let hasMessage = false;
+    port.onDisconnect.addListener(() => {
+      browser.test.assertFalse(disconnected, "onDisconnect should fire once");
+      disconnected = true;
+      browser.test.assertTrue(hasMessage, "Expected onMessage before onDisconnect");
+      delayedNotifyPass("Received onDisconnect from closing frame");
+    });
+    port.onMessage.addListener(msg => {
+      browser.test.assertFalse(hasMessage, "onMessage should fire once");
+      hasMessage = true;
+      browser.test.assertFalse(disconnected, "Should get message before disconnect");
+      browser.test.assertEq("from frame", msg, "Expected message from frame");
+    });
+
+    port.postMessage("reply to closing frame");
+  });
+}
+function connect_contentScript(testType) {
+  let port = browser.runtime.connect({name: "port from frame"});
+  port.onMessage.addListener(msg => {
+    // The frame has been removed, so we should not get a reply.
+    browser.test.fail(`Unexpected reply: ${msg}`);
+  });
+  port.postMessage("from frame");
+
+  // Removing the frame or window should disconnect the port.
+  if (testType == "frame") {
+    frameElement.remove();
+  } else {
+    window.close();
+  }
+}
+
+// `testType` is "window" or "frame".
+function createTestExtension(testType, backgroundScript, contentScript) {
+  // Make a roundtrip between the background page and the test runner (which is
+  // in the same process as the content script) to make sure that we record a
+  // failure in case the content script's sendMessage or onMessage handlers are
+  // called even after the frame or window was removed.
+  function delayedNotifyPass(msg) {
+    browser.test.onMessage.addListener((type, echoMsg) => {
+      if (type == "pong") {
+        browser.test.assertEq(msg, echoMsg, "Echoed reply should be the same");
+        browser.test.notifyPass(msg);
+      }
+    });
+    browser.test.log("Starting ping-pong to flush messages...");
+    browser.test.sendMessage("ping", msg);
+  }
+  let extension = ExtensionTestUtils.loadExtension({
+    background: `${delayedNotifyPass};(${backgroundScript})();`,
+    manifest: {
+      content_scripts: [{
+        js: ["contentscript.js"],
+        all_frames: testType == "frame",
+        matches: ["http://mochi.test/*/file_sample.html"],
+      }],
+    },
+    files: {
+      "contentscript.js": `(${contentScript})("${testType}");`,
+    },
+  });
+  extension.awaitMessage("ping").then(msg => {
+    extension.sendMessage("pong", msg);
+  });
+  return extension;
+}
+
+add_task(function* testSendMessage_and_remove_frame() {
+  let extension = createTestExtension("frame", sendMessage_background, sendMessage_contentScript);
+  yield extension.startup();
+
+  let frame = document.createElement("iframe");
+  frame.src = "file_sample.html";
+  document.body.appendChild(frame);
+
+  yield extension.awaitFinish("Received sendMessage from closing frame");
+  yield extension.unload();
+});
+
+add_task(function* testConnect_and_remove_frame() {
+  let extension = createTestExtension("frame", connect_background, connect_contentScript);
+  yield extension.startup();
+
+  let frame = document.createElement("iframe");
+  frame.src = "file_sample.html";
+  document.body.appendChild(frame);
+
+  yield extension.awaitFinish("Received onDisconnect from closing frame");
+  yield extension.unload();
+});
+
+add_task(function* testSendMessage_and_remove_window() {
+  let extension = createTestExtension("window", sendMessage_background, sendMessage_contentScript);
+  yield extension.startup();
+
+  window.open("file_sample.html");
+
+  yield extension.awaitFinish("Received sendMessage from closing frame");
+  yield extension.unload();
+});
+
+add_task(function* testConnect_and_remove_window() {
+  let extension = createTestExtension("window", connect_background, connect_contentScript);
+  yield extension.startup();
+
+  window.open("file_sample.html");
+
+  yield extension.awaitFinish("Received onDisconnect from closing frame");
+  yield extension.unload();
+});
+
+</script>
+</body>
+</html>
