diff --git a/browser/app/profile/firefox.js b/browser/app/profile/firefox.js
index ae1c03b1d6fc..a3058fa7713e 100644
--- a/browser/app/profile/firefox.js
+++ b/browser/app/profile/firefox.js
@@ -1044,7 +1044,7 @@ pref("dom.ipc.plugins.sandbox-level.flash", 0);
 // See - security/sandbox/win/src/sandboxbroker/sandboxBroker.cpp
 // SetSecurityLevelForContentProcess() for what the different settings mean.
 #if defined(NIGHTLY_BUILD)
-pref("security.sandbox.content.level", 3);
+pref("security.sandbox.content.level", 2);
 #else
 pref("security.sandbox.content.level", 1);
 #endif