diff --git a/app/models/site.rb b/app/models/site.rb
index 2a1d9b3..7c42349 100644
--- a/app/models/site.rb
+++ b/app/models/site.rb
@@ -99,6 +99,10 @@ class Site
     @collections
   end
 
+  def collections_names
+    @jekyll.config['collections'].keys
+  end
+
   # Los posts de este sitio, si el sitio está traducido, trae los posts
   # del idioma actual, porque _posts va a estar vacío
   def posts
@@ -114,11 +118,10 @@ class Site
   #
   # Devuelve nil si la colección no existe
   def posts_for(collection)
-    return unless @jekyll.config['collections'].key? collection
-
+    return unless collections_names.include? collection
     # Si pedimos 'posts' pero estamos en un sitio traducido, traemos el
     # idioma actual
-    collection = I18n.locale.to_s if collection == 'posts' && i18n?
+    collection = default_lang if collection == 'posts' && i18n?
 
     _collection = @collections[collection]
     return _collection if _collection
@@ -149,6 +152,9 @@ class Site
 
   def everything_of(attr, lang: nil)
     collection = lang || 'posts'
+
+    return [] unless collections_names.include? collection
+
     posts_for(collection).map do |p|
       p.get_front_matter attr
     end.flatten.uniq