diff --git a/app/services/post_service.rb b/app/services/post_service.rb
index c82953e3..83d30a50 100644
--- a/app/services/post_service.rb
+++ b/app/services/post_service.rb
@@ -199,10 +199,7 @@ PostService = Struct.new(:site, :usuarie, :post, :params, keyword_init: true) do
         end
 
         associated_posts(value - value_was).each do |add_post|
-          add_post[inverse_attribute].value << post.uuid.value
-          add_post[inverse_attribute].value.uniq!
-
-          associated_posts_to_save << add_post
+          add_relation_to(add_post[inverse_attribute], post.uuid.value)
         end
       when 'has_many'
         associated_posts(value_was - value).each do |remove_post|
@@ -214,9 +211,7 @@ PostService = Struct.new(:site, :usuarie, :post, :params, keyword_init: true) do
             remove_relation_from(remove_post[attribute], add_post.uuid.value)
           end
 
-          add_post[inverse_attribute].value = post.uuid.value
-
-          associated_posts_to_save << add_post
+          add_relation_to(add_post[inverse_attribute], post.uuid.value)
         end
       when 'belongs_to'
         if value_was.present?
@@ -226,10 +221,7 @@ PostService = Struct.new(:site, :usuarie, :post, :params, keyword_init: true) do
         end
 
         associated_posts(value).each do |add_post|
-          add_post[inverse_attribute].value << post.uuid.value
-          add_post[inverse_attribute].value.uniq!
-
-          associated_posts_to_save << add_post
+          add_relation_to(add_post[inverse_attribute], post.uuid.value)
         end
       when 'locales'
       end
@@ -246,4 +238,17 @@ PostService = Struct.new(:site, :usuarie, :post, :params, keyword_init: true) do
     associated_posts_to_save << metadata.post
     nil
   end
+
+  # @todo El validador ya debería eliminar valores duplicados
+  def add_relation_to(metadata, value)
+    case metadata.value
+    when Array
+      metadata.value << value
+      metadata.uniq!
+    when String then metadata.value = value
+    end
+
+    associated_posts_to_save << metadata.post
+    nil
+  end
 end