diff --git a/toolkit/components/jsdownloads/test/unit/head.js b/toolkit/components/jsdownloads/test/unit/head.js
index 64a330db6e3..6fb88964c43 100644
--- a/toolkit/components/jsdownloads/test/unit/head.js
+++ b/toolkit/components/jsdownloads/test/unit/head.js
@@ -683,6 +683,14 @@ add_task(function test_common_initialize()
   gHttpServer = new HttpServer();
   gHttpServer.registerDirectory("/", do_get_file("../data"));
   gHttpServer.start(-1);
+  do_register_cleanup(() => {
+    return new Promise(resolve => {
+      // Ensure all the pending HTTP requests have a chance to finish.
+      continueResponses();
+      // Stop the HTTP server, calling resolve when it's done.
+      gHttpServer.stop(resolve);
+    });
+  });
 
   // Cache locks might prevent concurrent requests to the same resource, and
   // this may block tests that use the interruptible handlers.
diff --git a/toolkit/components/jsdownloads/test/unit/tail.js b/toolkit/components/jsdownloads/test/unit/tail.js
deleted file mode 100644
index b34fc79bc32..00000000000
--- a/toolkit/components/jsdownloads/test/unit/tail.js
+++ /dev/null
@@ -1,25 +0,0 @@
-/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- */
-/* vim: set ts=2 et sw=2 tw=80: */
-/* Any copyright is dedicated to the Public Domain.
- * http://creativecommons.org/publicdomain/zero/1.0/ */
-
-/**
- * Provides infrastructure for automated download components tests.
- */
-
-"use strict";
-
-////////////////////////////////////////////////////////////////////////////////
-//// Termination functions common to all tests
-
-add_task(function* test_common_terminate()
-{
-  // Ensure all the pending HTTP requests have a chance to finish.
-  continueResponses();
-
-  // Stop the HTTP server.  We must do this inside a task in "tail.js" until the
-  // xpcshell testing framework supports asynchronous termination functions.
-  let deferred = Promise.defer();
-  gHttpServer.stop(deferred.resolve);
-  yield deferred.promise;
-});
diff --git a/toolkit/components/jsdownloads/test/unit/test_DownloadCore.js b/toolkit/components/jsdownloads/test/unit/test_DownloadCore.js
index f5290b3fede..e86a83dd982 100644
--- a/toolkit/components/jsdownloads/test/unit/test_DownloadCore.js
+++ b/toolkit/components/jsdownloads/test/unit/test_DownloadCore.js
@@ -87,9 +87,3 @@ add_task(function test_DownloadError()
   do_check_true(error.becauseBlocked);
   do_check_true(error.becauseBlockedByParentalControls);
 });
-
-////////////////////////////////////////////////////////////////////////////////
-//// Termination
-
-var tailFile = do_get_file("tail.js");
-Services.scriptloader.loadSubScript(NetUtil.newURI(tailFile).spec);
diff --git a/toolkit/components/jsdownloads/test/unit/test_DownloadIntegration.js b/toolkit/components/jsdownloads/test/unit/test_DownloadIntegration.js
index 6e8a51d5e96..316407a81ee 100644
--- a/toolkit/components/jsdownloads/test/unit/test_DownloadIntegration.js
+++ b/toolkit/components/jsdownloads/test/unit/test_DownloadIntegration.js
@@ -415,9 +415,3 @@ add_task(function* test_exit_private_browsing()
 
   continueResponses();
 });
-
-////////////////////////////////////////////////////////////////////////////////
-//// Termination
-
-var tailFile = do_get_file("tail.js");
-Services.scriptloader.loadSubScript(NetUtil.newURI(tailFile).spec);
diff --git a/toolkit/components/jsdownloads/test/unit/test_DownloadLegacy.js b/toolkit/components/jsdownloads/test/unit/test_DownloadLegacy.js
index 101fa8cb06c..3a68eb8c45c 100644
--- a/toolkit/components/jsdownloads/test/unit/test_DownloadLegacy.js
+++ b/toolkit/components/jsdownloads/test/unit/test_DownloadLegacy.js
@@ -16,9 +16,3 @@ var gUseLegacySaver = true;
 
 var scriptFile = do_get_file("common_test_Download.js");
 Services.scriptloader.loadSubScript(NetUtil.newURI(scriptFile).spec);
-
-////////////////////////////////////////////////////////////////////////////////
-//// Termination
-
-var tailFile = do_get_file("tail.js");
-Services.scriptloader.loadSubScript(NetUtil.newURI(tailFile).spec);
diff --git a/toolkit/components/jsdownloads/test/unit/test_DownloadList.js b/toolkit/components/jsdownloads/test/unit/test_DownloadList.js
index 550ce7eda90..dfb97b6f45b 100644
--- a/toolkit/components/jsdownloads/test/unit/test_DownloadList.js
+++ b/toolkit/components/jsdownloads/test/unit/test_DownloadList.js
@@ -564,9 +564,3 @@ add_task(function* test_DownloadSummary_notifications()
   yield download.start();
   do_check_true(receivedOnSummaryChanged);
 });
-
-////////////////////////////////////////////////////////////////////////////////
-//// Termination
-
-var tailFile = do_get_file("tail.js");
-Services.scriptloader.loadSubScript(NetUtil.newURI(tailFile).spec);
diff --git a/toolkit/components/jsdownloads/test/unit/test_DownloadStore.js b/toolkit/components/jsdownloads/test/unit/test_DownloadStore.js
index fc2df08e452..f2a44c19ca6 100644
--- a/toolkit/components/jsdownloads/test/unit/test_DownloadStore.js
+++ b/toolkit/components/jsdownloads/test/unit/test_DownloadStore.js
@@ -305,9 +305,3 @@ add_task(function* test_save_reload_unknownProperties()
   do_check_eq(itemsForLoad[2].saver._unknownProperties.saver2,
               "download3saver2");
 });
-
-////////////////////////////////////////////////////////////////////////////////
-//// Termination
-
-var tailFile = do_get_file("tail.js");
-Services.scriptloader.loadSubScript(NetUtil.newURI(tailFile).spec);
diff --git a/toolkit/components/jsdownloads/test/unit/test_Downloads.js b/toolkit/components/jsdownloads/test/unit/test_Downloads.js
index ce153479889..507950355c3 100644
--- a/toolkit/components/jsdownloads/test/unit/test_Downloads.js
+++ b/toolkit/components/jsdownloads/test/unit/test_Downloads.js
@@ -193,9 +193,3 @@ add_task(function* test_getTemporaryDownloadsDirectory()
   let downloadDir = yield Downloads.getTemporaryDownloadsDirectory();
   do_check_neq(downloadDir, "");
 });
-
-////////////////////////////////////////////////////////////////////////////////
-//// Termination
-
-var tailFile = do_get_file("tail.js");
-Services.scriptloader.loadSubScript(NetUtil.newURI(tailFile).spec);
diff --git a/toolkit/components/jsdownloads/test/unit/test_PrivateTemp.js b/toolkit/components/jsdownloads/test/unit/test_PrivateTemp.js
index ca8fd4df1fb..138be8d2991 100644
--- a/toolkit/components/jsdownloads/test/unit/test_PrivateTemp.js
+++ b/toolkit/components/jsdownloads/test/unit/test_PrivateTemp.js
@@ -22,11 +22,3 @@ add_task(function* test_private_temp() {
   // 488 is the decimal value of 0700.
   equal(targetFile.parent.permissions, 448);
 });
-
-
-////////////////////////////////////////////////////////////////////////////////
-//// Termination
-
-var tailFile = do_get_file("tail.js");
-Services.scriptloader.loadSubScript(NetUtil.newURI(tailFile).spec);
-
diff --git a/toolkit/components/jsdownloads/test/unit/xpcshell.ini b/toolkit/components/jsdownloads/test/unit/xpcshell.ini
index b7ee9d44fc6..60d4fa7407d 100644
--- a/toolkit/components/jsdownloads/test/unit/xpcshell.ini
+++ b/toolkit/components/jsdownloads/test/unit/xpcshell.ini
@@ -7,7 +7,6 @@ skip-if = toolkit == 'android' || toolkit == 'gonk'
 #       the "add_test_task" function, that does not work properly in tail files.
 support-files =
   common_test_Download.js
-  tail.js
 
 [test_DownloadCore.js]
 [test_DownloadImport.js]