diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index acd0134..b3d355b 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -8,13 +8,14 @@ class ApplicationController < ActionController::Base
 
   before_action :prepare_exception_notifier
   before_action :configure_permitted_parameters, if: :devise_controller?
+  before_action :redirect_to_site_name!, only: %i[index show edit new], if: :site_id_contains_hostname?
   around_action :set_locale
 
   rescue_from ActionController::RoutingError, with: :page_not_found
   rescue_from ActionController::ParameterMissing, with: :page_not_found
 
   before_action do
-    Rack::MiniProfiler.authorize_request if current_usuarie&.email&.ends_with?('@' + ENV.fetch('SUTTY', 'sutty.nl'))
+    Rack::MiniProfiler.authorize_request if Rails.env.development?
   end
 
   # No tenemos índice de sutty, vamos directamente a ver el listado de
@@ -29,15 +30,11 @@ class ApplicationController < ActionController::Base
     /[a-f0-9]{8}-([a-f0-9]{4}-){3}[a-f0-9]{12}/ =~ string
   end
 
-  # Encontrar un sitio por su nombre
+  # Encontrar un sitio por su nombre.
   def find_site
-    id = params[:site_id] || params[:id]
-
-    unless (site = current_usuarie.sites.find_by_name(id))
-      raise SiteNotFound
+    current_usuarie.sites.find_by_name(site_id).tap do |site|
+      raise SiteNotFound unless site
     end
-
-    site
   end
 
   # Devuelve el idioma actual y si no lo encuentra obtiene uno por
@@ -62,6 +59,39 @@ class ApplicationController < ActionController::Base
     render 'application/page_not_found', status: :not_found
   end
 
+  # Retrocompatibilidad con sitios cuyo nombre era su hostname.
+  #
+  # @see Deploy
+  def site_id_contains_hostname?
+    site_id&.end_with? '.'
+  end
+
+  # Redirigir a la misma URL con el site_id cambiado.
+  #
+  # TODO: Eliminar cuando detectemos que no hay más redirecciones.
+  def redirect_to_site_name!
+    params.permit!
+    params[:site_id] = Deploy.site_name_from_hostname(site_id[0..-2])
+
+    redirect_to params, status: :moved_permanently
+  end
+
+  # Los controladores dentro de SitesController van a usar site_id
+  # mientras que SiteController va a usar ID.
+  #
+  # @see SitesController
+  # @return [String,Nil]
+  def site_id
+    @site_id ||= params[:site_id]
+  end
+
+  # El sitio actual
+  #
+  # @return [Site]
+  def site
+    @site ||= find_site
+  end
+
   protected
 
   def configure_permitted_parameters
diff --git a/app/controllers/collaborations_controller.rb b/app/controllers/collaborations_controller.rb
index 2caa127..ab13ef5 100644
--- a/app/controllers/collaborations_controller.rb
+++ b/app/controllers/collaborations_controller.rb
@@ -7,7 +7,7 @@ class CollaborationsController < ApplicationController
   include Pundit
 
   def collaborate
-    @site = Site.find_by_name(params[:site_id])
+    @site = find_site
     authorize Collaboration.new(@site)
 
     @invitade = current_usuarie || @site.usuaries.build
@@ -21,7 +21,7 @@ class CollaborationsController < ApplicationController
   #
   # * Si le usuarie existe y no está logueade, pedirle la contraseña
   def accept_collaboration
-    @site = Site.find_by_name(params[:site_id])
+    @site = find_site
     authorize Collaboration.new(@site)
 
     @invitade = current_usuarie
diff --git a/app/controllers/sites_controller.rb b/app/controllers/sites_controller.rb
index bdaa901..d991423 100644
--- a/app/controllers/sites_controller.rb
+++ b/app/controllers/sites_controller.rb
@@ -139,8 +139,10 @@ class SitesController < ApplicationController
 
   private
 
-  def site
-    @site ||= find_site
+  # En los controladores dentro de este controlador vamos a usar :id
+  # para obtener el nombre.
+  def site_id
+    @site_id ||= params[:id]
   end
 
   def site_params