diff --git a/toolkit/mozapps/extensions/src/nsBlocklistService.js b/toolkit/mozapps/extensions/src/nsBlocklistService.js
index 1a0262f87034..1d689dbc756b 100644
--- a/toolkit/mozapps/extensions/src/nsBlocklistService.js
+++ b/toolkit/mozapps/extensions/src/nsBlocklistService.js
@@ -382,10 +382,6 @@ Blocklist.prototype = {
 
   observe: function (aSubject, aTopic, aData) {
     switch (aTopic) {
-    case "app-startup":
-      gOS.addObserver(this, "profile-after-change", false);
-      gOS.addObserver(this, "quit-application", false);
-      break;
     case "profile-after-change":
       gLoggingEnabled = getPref("getBoolPref", PREF_EM_LOGGING_ENABLED, false);
       gBlocklistEnabled = getPref("getBoolPref", PREF_BLOCKLIST_ENABLED, true);
@@ -397,14 +393,10 @@ Blocklist.prototype = {
       var interval = getPref("getIntPref", PREF_BLOCKLIST_INTERVAL, 86400);
       tm.registerTimer("blocklist-background-update-timer", this, interval);
       break;
-    case "quit-application":
-      gOS.removeObserver(this, "profile-after-change");
-      gOS.removeObserver(this, "quit-application");
-      gPref.removeObserver("extensions.blocklist.", this);
-      break;
     case "xpcom-shutdown":
       gOS.removeObserver(this, "xpcom-shutdown");
       gOS = null;
+      gPref.removeObserver("extensions.blocklist.", this);
       gPref = null;
       gConsole = null;
       gVersionChecker = null;
@@ -927,10 +919,7 @@ Blocklist.prototype = {
   QueryInterface: XPCOMUtils.generateQI([Ci.nsIObserver,
                                          Ci.nsIBlocklistService,
                                          Ci.nsITimerCallback]),
-  _xpcom_categories: [{
-    category: "app-startup",
-    service: true
-  }]
+  _xpcom_categories: [{ category: "profile-after-change" }]
 };
 
 /**
diff --git a/toolkit/mozapps/extensions/src/nsExtensionManager.js.in b/toolkit/mozapps/extensions/src/nsExtensionManager.js.in
index 298f04402563..59aed5d27115 100644
--- a/toolkit/mozapps/extensions/src/nsExtensionManager.js.in
+++ b/toolkit/mozapps/extensions/src/nsExtensionManager.js.in
@@ -2519,10 +2519,6 @@ ExtensionManager.prototype = {
    */
   observe: function EM_observe(subject, topic, data) {
     switch (topic) {
-    case "app-startup":
-      gOS.addObserver(this, "profile-after-change", false);
-      gOS.addObserver(this, "quit-application", false);
-      break;
     case "profile-after-change":
       this._profileSelected();
       break;
@@ -2532,10 +2528,6 @@ ExtensionManager.prototype = {
     case "offline-requested":
       this._confirmCancelDownloadsOnOffline(subject);
       break;
-    case "quit-application":
-      gOS.removeObserver(this, "profile-after-change");
-      gOS.removeObserver(this, "quit-application");
-      break;
     case "xpcom-shutdown":
       this._shutdown();
       break;
@@ -5961,7 +5953,7 @@ ExtensionManager.prototype = {
   classDescription: "Extension Manager",
   contractID: "@mozilla.org/extensions/manager;1",
   classID: Components.ID("{8A115FAA-7DCB-4e8f-979B-5F53472F51CF}"),
-  _xpcom_categories: [{ category: "app-startup", service: true }],
+  _xpcom_categories: [{ category: "profile-after-change" }],
   _xpcom_factory: {
     createInstance: function(outer, iid) {
       if (outer != null)
diff --git a/toolkit/mozapps/extensions/test/unit/head_extensionmanager.js b/toolkit/mozapps/extensions/test/unit/head_extensionmanager.js
index f851b8ffabbe..9ead959468dd 100644
--- a/toolkit/mozapps/extensions/test/unit/head_extensionmanager.js
+++ b/toolkit/mozapps/extensions/test/unit/head_extensionmanager.js
@@ -216,7 +216,6 @@ function startupEM()
                   .getService(Components.interfaces.nsIExtensionManager);
   
   gEM.QueryInterface(Components.interfaces.nsIObserver);
-  gEM.observe(null, "app-startup", null);
   gEM.observe(null, "profile-after-change", "startup");
 
   // First run is a new profile which nsAppRunner would consider as an update
diff --git a/toolkit/mozapps/extensions/test/unit/test_bug430120.js b/toolkit/mozapps/extensions/test/unit/test_bug430120.js
index 4e120c24c865..68600e9df762 100644
--- a/toolkit/mozapps/extensions/test/unit/test_bug430120.js
+++ b/toolkit/mozapps/extensions/test/unit/test_bug430120.js
@@ -131,7 +131,6 @@ function run_test() {
   gBlocklist = Components.classes["@mozilla.org/extensions/blocklist;1"]
                          .getService(Components.interfaces.nsIBlocklistService)
                          .QueryInterface(Components.interfaces.nsIObserver);
-  gBlocklist.observe(null, "app-startup", "");
   gBlocklist.observe(null, "profile-after-change", "");
 
   do_check_true(timerService.hasTimer(BLOCKLIST_TIMER));