diff --git a/toolkit/mozapps/extensions/AddonManager.jsm b/toolkit/mozapps/extensions/AddonManager.jsm
index f71e9a30ebf0..80680d148526 100644
--- a/toolkit/mozapps/extensions/AddonManager.jsm
+++ b/toolkit/mozapps/extensions/AddonManager.jsm
@@ -47,10 +47,11 @@ Components.utils.import("resource://gre/modules/Services.jsm");
 
 var EXPORTED_SYMBOLS = [ "AddonManager", "AddonManagerPrivate" ];
 
+const CATEGORY_PROVIDER_MODULE = "addon-provider-module";
+
 // A list of providers to load by default
-const PROVIDERS = [
+const DEFAULT_PROVIDERS = [
   "resource://gre/modules/XPIProvider.jsm",
-  "resource://gre/modules/PluginProvider.jsm",
   "resource://gre/modules/LightweightThemeManager.jsm"
 ];
 
@@ -191,15 +192,32 @@ var AddonManagerInternal = {
     }
 
     // Ensure all default providers have had a chance to register themselves
-    PROVIDERS.forEach(function(url) {
+    DEFAULT_PROVIDERS.forEach(function(url) {
       try {
         Components.utils.import(url, {});
       }
       catch (e) {
-        ERROR("Exception loading provider \"" + url + "\": " + e);
+        ERROR("Exception loading default provider \"" + url + "\": " + e);
       }
     });
 
+    // Load any providers registered in the category manager
+    let catman = Cc["@mozilla.org/categorymanager;1"].
+                 getService(Ci.nsICategoryManager);
+    let entries = catman.enumerateCategory(CATEGORY_PROVIDER_MODULE);
+    while (entries.hasMoreElements()) {
+      let entry = entries.getNext().QueryInterface(Ci.nsISupportsCString).data;
+      let url = catman.getCategoryEntry(CATEGORY_PROVIDER_MODULE, entry);
+
+      try {
+        Components.utils.import(url, {});
+      }
+      catch (e) {
+        ERROR("Exception loading provider " + entry + " from category \"" +
+              url + "\": " + e);
+      }
+    }
+
     let needsRestart = false;
     this.providers.forEach(function(provider) {
       callProvider(provider, "startup");
diff --git a/toolkit/mozapps/extensions/Makefile.in b/toolkit/mozapps/extensions/Makefile.in
index ba69642307ee..ec8728beed10 100644
--- a/toolkit/mozapps/extensions/Makefile.in
+++ b/toolkit/mozapps/extensions/Makefile.in
@@ -72,11 +72,15 @@ EXTRA_PP_JS_MODULES = \
   AddonManager.jsm \
   AddonRepository.jsm \
   XPIProvider.jsm \
-  PluginProvider.jsm \
   AddonUpdateChecker.jsm \
   AddonLogging.jsm \
   $(NULL)
 
+ifdef MOZ_PLUGINS
+  EXTRA_PP_JS_MODULES += PluginProvider.jsm
+  DEFINES += -DMOZ_PLUGINS
+endif
+
 EXTRA_JS_MODULES = \
   LightweightThemeManager.jsm \
   $(NULL)
diff --git a/toolkit/mozapps/extensions/extensions.manifest b/toolkit/mozapps/extensions/extensions.manifest
index 54626872d896..dc34b684f489 100644
--- a/toolkit/mozapps/extensions/extensions.manifest
+++ b/toolkit/mozapps/extensions/extensions.manifest
@@ -8,3 +8,6 @@ component {7beb3ba8-6ec3-41b4-b67c-da89b8518922} amContentHandler.js
 contract @mozilla.org/uriloader/content-handler;1?type=application/x-xpinstall {7beb3ba8-6ec3-41b4-b67c-da89b8518922}
 component {0f38e086-89a3-40a5-8ffc-9b694de1d04a} amWebInstallListener.js
 contract @mozilla.org/addons/web-install-listener;1 {0f38e086-89a3-40a5-8ffc-9b694de1d04a}
+#ifdef MOZ_PLUGINS
+category addon-provider-module PluginProvider resource://gre/modules/PluginProvider.jsm
+#endif