--- a/toolkit/moz.configure
+++ b/toolkit/moz.configure
@@ -545,16 +545,28 @@ option(env='MOZ_PHOTON_ANIMATIONS',
 @depends('MOZ_PHOTON_ANIMATIONS')
 def photon_animations(value):
     if value:
         return bool(value)
 
 set_config('MOZ_PHOTON_ANIMATIONS', photon_animations)
 set_define('MOZ_PHOTON_ANIMATIONS', photon_animations)
 
+option(env='MOZ_PHOTON_THEME',
+       help='Enable Photon theme',
+       default=delayed_getattr(milestone, 'is_nightly'))
+
+@depends('MOZ_PHOTON_THEME')
+def photon_theme(value):
+    if value:
+        return bool(value)
+
+set_config('MOZ_PHOTON_THEME', photon_theme)
+set_define('MOZ_PHOTON_THEME', photon_theme)
+
 @depends('MOZ_PLACES', 'MOZ_ANDROID_HISTORY')
 def check_places_and_android_history(places, android_history):
     if places and android_history:
         die('Cannot use MOZ_ANDROID_HISTORY alongside MOZ_PLACES.')
 
 # Permissions system
 # ==============================================================
 option(name='--disable-permissions',