--- a/toolkit/mozapps/extensions/test/xpcshell/head_addons.js
+++ b/toolkit/mozapps/extensions/test/xpcshell/head_addons.js
@@ -75,17 +75,16 @@ const LEGACY_NON_RESTARTLESS_TESTS = new
   "test_bug397778.js",
   "test_bug425657.js",
   "test_bug455906.js",
   "test_bug470377_1.js",
   "test_bug470377_2.js",
   "test_bug470377_3.js",
   "test_bug470377_4.js",
   "test_bug655254.js",
-  "test_cacheflush.js",
   "test_checkcompatibility.js",
   "test_signed_verify.js",
   "test_strictcompatibility.js",
   "test_syncGUID.js",
   "test_upgrade.js",
 ]);
 
 if (LEGACY_NON_RESTARTLESS_TESTS.has(_TEST_FILE[0].replace(/.*\//, ""))) {

--- a/toolkit/mozapps/extensions/test/xpcshell/test_cacheflush.js
+++ b/toolkit/mozapps/extensions/test/xpcshell/test_cacheflush.js
@@ -19,26 +19,16 @@ var CacheFlushObserver = {
     ok(aSubject instanceof AM_Ci.nsIFile);
     equal(aSubject.path, gExpectedFile.path);
     gCacheFlushCount++;
   }
 };
 
 const ADDONS = [
   {
-    id: "addon1@tests.mozilla.org",
-    version: "2.0",
-    name: "Cache Flush Test",
-
-    targetApplications: [{
-      id: "xpcshell@tests.mozilla.org",
-      minVersion: "1",
-      maxVersion: "1" }],
-  },
-  {
     id: "addon2@tests.mozilla.org",
     version: "2.0",
 
     name: "Cache Flush Test",
     bootstrap: true,
 
     targetApplications: [{
       id: "xpcshell@tests.mozilla.org",
@@ -51,69 +41,19 @@ const XPIS = ADDONS.map(addon => createT
 
 add_task(async function setup() {
   Services.obs.addObserver(CacheFlushObserver, "flush-cache-entry");
   createAppInfo("xpcshell@tests.mozilla.org", "XPCShell", "1", "2");
 
   await promiseStartupManager();
 });
 
-// Tests that the cache is flushed when cancelling a pending install
-add_task(async function test_flush_pending_install() {
-  let install = await AddonManager.getInstallForFile(XPIS[0]);
-  await promiseCompleteInstall(install);
-
-  // We should flush the staged XPI when cancelling the install
-  gExpectedFile = gProfD.clone();
-  gExpectedFile.append("extensions");
-  gExpectedFile.append("staged");
-  gExpectedFile.append("addon1@tests.mozilla.org.xpi");
-  install.cancel();
-
-  equal(gCacheFlushCount, 1);
-  gExpectedFile = null;
-  gCacheFlushCount = 0;
-});
-
-// Tests that the cache is flushed when uninstalling an add-on
-add_task(async function test_flush_uninstall() {
-  await promiseInstallFile(XPIS[0]);
-
-  // Installing will flush the staged XPI during startup
-  gExpectedFile = gProfD.clone();
-  gExpectedFile.append("extensions");
-  gExpectedFile.append("staged");
-  gExpectedFile.append("addon1@tests.mozilla.org.xpi");
-
-  await promiseRestartManager();
-
-  equal(gCacheFlushCount, 1);
-  gExpectedFile = null;
-  gCacheFlushCount = 0;
-
-  let addon = await AddonManager.getAddonByID("addon1@tests.mozilla.org");
-  // We should flush the installed XPI when uninstalling
-  ok(addon != null);
-  addon.uninstall();
-  equal(gCacheFlushCount, 0);
-
-  gExpectedFile = gProfD.clone();
-  gExpectedFile.append("extensions");
-  gExpectedFile.append("addon1@tests.mozilla.org.xpi");
-
-  await promiseRestartManager();
-
-  equal(gCacheFlushCount, 1);
-  gExpectedFile = null;
-  gCacheFlushCount = 0;
-});
-
 // Tests that the cache is flushed when installing a restartless add-on
 add_task(async function test_flush_restartless_install() {
-  let install = await AddonManager.getInstallForFile(XPIS[1]);
+  let install = await AddonManager.getInstallForFile(XPIS[0]);
 
   await new Promise(resolve => {
     install.addListener({
       onInstallStarted() {
         // We should flush the staged XPI when completing the install
         gExpectedFile = gProfD.clone();
         gExpectedFile.append("extensions");
         gExpectedFile.append("staged");