diff --git a/app/controllers/api/v1/sites_controller.rb b/app/controllers/api/v1/sites_controller.rb
index 185d0b24..05abc38a 100644
--- a/app/controllers/api/v1/sites_controller.rb
+++ b/app/controllers/api/v1/sites_controller.rb
@@ -18,10 +18,16 @@ module Api
         name.end_with?('.') ? name[0..-2] : "#{name}.#{Site.domain}"
       end
 
+      def subdomain?(name)
+        name.end_with? ".#{Site.domain}"
+      end
+
       # Dominios alternativos
       def alternative_names
         (DeployAlternativeDomain.all.map(&:hostname) + DeployLocalizedDomain.all.map(&:hostname)).map do |name|
           canonicalize name
+        end.reject do |name|
+          subdomain? name
         end
       end
 
@@ -34,6 +40,8 @@ module Api
             .or(Site.where(colaboracion_anonima: true))
             .select("'api.' || name as name").map(&:name).map do |name|
               canonicalize name
+            end.reject do |name|
+              subdomain? name
             end
       end