diff --git a/mozilla/browser/components/sessionstore/src/nsSessionStore.js b/mozilla/browser/components/sessionstore/src/nsSessionStore.js
index 84b614ddfef..348dca929de 100644
--- a/mozilla/browser/components/sessionstore/src/nsSessionStore.js
+++ b/mozilla/browser/components/sessionstore/src/nsSessionStore.js
@@ -89,7 +89,7 @@ const PRIVACY_FULL = 2;
 /* :::::::: Pref Defaults :::::::::::::::::::: */
 
 // whether the service is enabled
-const DEFAULT_ENABLED = true;
+const DEFAULT_ENABLED = false;
 
 // minimal interval between two save operations (in milliseconds)
 const DEFAULT_INTERVAL = 10000;