--- a/toolkit/mozapps/extensions/internal/XPIProvider.jsm
+++ b/toolkit/mozapps/extensions/internal/XPIProvider.jsm
@@ -116,16 +116,17 @@ const PREF_INSTALL_REQUIRESECUREORIGIN =
 const PREF_INSTALL_DISTRO_ADDONS      = "extensions.installDistroAddons";
 const PREF_BRANCH_INSTALLED_ADDON     = "extensions.installedDistroAddon.";
 const PREF_INTERPOSITION_ENABLED      = "extensions.interposition.enabled";
 const PREF_SYSTEM_ADDON_SET           = "extensions.systemAddonSet";
 const PREF_SYSTEM_ADDON_UPDATE_URL    = "extensions.systemAddon.update.url";
 const PREF_E10S_BLOCK_ENABLE          = "extensions.e10sBlocksEnabling";
 const PREF_E10S_ADDON_BLOCKLIST       = "extensions.e10s.rollout.blocklist";
 const PREF_E10S_ADDON_POLICY          = "extensions.e10s.rollout.policy";
+const PREF_E10S_HAS_NONEXEMPT_ADDON   = "extensions.e10s.rollout.hasAddon";
 
 const PREF_EM_MIN_COMPAT_APP_VERSION      = "extensions.minCompatibleAppVersion";
 const PREF_EM_MIN_COMPAT_PLATFORM_VERSION = "extensions.minCompatiblePlatformVersion";
 
 const PREF_CHECKCOMAT_THEMEOVERRIDE   = "extensions.checkCompatibility.temporaryThemeOverride_minAppVersion";
 
 const PREF_EM_HOTFIX_ID               = "extensions.hotfix.id";
 const PREF_EM_CERT_CHECKATTRIBUTES    = "extensions.hotfix.cert.checkAttributes";
@@ -4377,18 +4378,20 @@ this.XPIProvider = {
 
     // System add-ons are exempt
     let locName = aAddon._installLocation ? aAddon._installLocation.name
                                           : undefined;
     if (locName == KEY_APP_SYSTEM_DEFAULTS ||
         locName == KEY_APP_SYSTEM_ADDONS)
       return false;
 
-    if (isAddonPartOfE10SRollout(aAddon))
+    if (isAddonPartOfE10SRollout(aAddon)) {
+      Preferences.set(PREF_E10S_HAS_NONEXEMPT_ADDON, true);
       return false;
+    }
 
     logger.debug("Add-on " + aAddon.id + " blocks e10s rollout.");
     return true;
   },
 
   /**
    * In some cases having add-ons active blocks e10s but turning off e10s
    * requires a restart so some add-ons that are normally restartless will

--- a/toolkit/mozapps/extensions/internal/XPIProviderUtils.js
+++ b/toolkit/mozapps/extensions/internal/XPIProviderUtils.js
@@ -51,16 +51,17 @@ const FILE_XPI_ADDONS_LIST            = 
 // The last version of DB_SCHEMA implemented in SQLITE
 const LAST_SQLITE_DB_SCHEMA           = 14;
 const PREF_DB_SCHEMA                  = "extensions.databaseSchema";
 const PREF_PENDING_OPERATIONS         = "extensions.pendingOperations";
 const PREF_EM_ENABLED_ADDONS          = "extensions.enabledAddons";
 const PREF_EM_DSS_ENABLED             = "extensions.dss.enabled";
 const PREF_EM_AUTO_DISABLED_SCOPES    = "extensions.autoDisableScopes";
 const PREF_E10S_BLOCKED_BY_ADDONS     = "extensions.e10sBlockedByAddons";
+const PREF_E10S_HAS_NONEXEMPT_ADDON   = "extensions.e10s.rollout.hasAddon";
 
 const KEY_APP_PROFILE                 = "app-profile";
 const KEY_APP_SYSTEM_ADDONS           = "app-system-addons";
 const KEY_APP_SYSTEM_DEFAULTS         = "app-system-defaults";
 const KEY_APP_GLOBAL                  = "app-global";
 
 // Properties that only exist in the database
 const DB_METADATA        = ["syncGUID",
@@ -1403,16 +1404,18 @@ this.XPIDatabase = {
     logger.debug("Updating active state for add-on " + aAddon.id + " to " + aActive);
 
     aAddon.active = aActive;
     this.saveChanges();
   },
 
   updateAddonsBlockingE10s: function() {
     let blockE10s = false;
+
+    Preferences.set(PREF_E10S_HAS_NONEXEMPT_ADDON, false);
     for (let [, addon] of this.addonDB) {
       let active = (addon.visible && !addon.disabled && !addon.pendingUninstall);
 
       if (active && XPIProvider.isBlockingE10s(addon)) {
         blockE10s = true;
         break;
       }
     }