diff --git a/zephyr/models.py b/zephyr/models.py
index c64f4347aa..f72cdc4e46 100644
--- a/zephyr/models.py
+++ b/zephyr/models.py
@@ -535,7 +535,7 @@ def do_send_message(message, no_log=False):
             secret   = settings.SHARED_SECRET,
             message  = message.id,
             rendered = simplejson.dumps(rendered),
-            users    = ','.join(str(user.id) for user in recipients)))
+            users    = simplejson.dumps([str(user.id) for user in recipients])))
 
 class Subscription(models.Model):
     user_profile = models.ForeignKey(UserProfile)
diff --git a/zephyr/views.py b/zephyr/views.py
index d114ebcdd0..a556b5b5e6 100644
--- a/zephyr/views.py
+++ b/zephyr/views.py
@@ -678,7 +678,7 @@ def notify_new_message(request):
 
     # FIXME: better query
     users   = [UserProfile.objects.get(id=user)
-               for user in request.POST['users'].split(',')]
+               for user in simplejson.loads(request.POST['users'])]
     message = Message.objects.get(id=request.POST['message'])
 
     # Cause message.to_dict() to return the dicts already rendered in the other process.