--- a/b2g/app/b2g.js
+++ b/b2g/app/b2g.js
@@ -33,17 +33,16 @@
  * the provisions above, a recipient may use your version of this file under
  * the terms of any one of the MPL, the GPL or the LGPL.
  *
  * ***** END LICENSE BLOCK ***** */
 
 #filter substitution
 
 pref("toolkit.defaultChromeURI", "chrome://browser/content/shell.xul");
-pref("general.useragent.compatMode.firefox", true);
 pref("browser.chromeURL", "chrome://browser/content/");
 #ifdef MOZ_OFFICIAL_BRANDING
 pref("browser.homescreenURL", "file:///system/home/homescreen.html");
 #else
 pref("browser.homescreenURL", "file:///data/local/homescreen.html,file:///system/home/homescreen.html");
 #endif
 
 // URL for the dialer application.

--- a/b2g/confvars.sh
+++ b/b2g/confvars.sh
@@ -33,17 +33,18 @@
 # the provisions above, a recipient may use your version of this file under
 # the terms of any one of the MPL, the GPL or the LGPL.
 #
 # ***** END LICENSE BLOCK *****
 
 MOZ_APP_BASENAME=B2G
 MOZ_APP_VENDOR=Mozilla
 
-MOZ_APP_VERSION=11.0a1
+MOZ_APP_VERSION=13.0a1
+MOZ_APP_UA_NAME=Firefox
 
 MOZ_BRANDING_DIRECTORY=b2g/branding/unofficial
 MOZ_OFFICIAL_BRANDING_DIRECTORY=b2g/branding/official
 # MOZ_APP_DISPLAYNAME is set by branding/configure.sh
 
 MOZ_SAFE_BROWSING=
 MOZ_SERVICES_SYNC=