diff --git a/app/services/post_service.rb b/app/services/post_service.rb
index 23b54d11..ff2ac6bd 100644
--- a/app/services/post_service.rb
+++ b/app/services/post_service.rb
@@ -266,7 +266,7 @@ PostService = Struct.new(:site, :usuarie, :post, :params, keyword_init: true) do
     case metadata.value
     when Array
       metadata.value << value
-      metadata.uniq!
+      metadata.value.uniq!
     when String then metadata.value = value
     end