diff --git a/app/lib/activitypub/parser/status_parser.rb b/app/lib/activitypub/parser/status_parser.rb
index 5a434ed91..fecfd0e34 100644
--- a/app/lib/activitypub/parser/status_parser.rb
+++ b/app/lib/activitypub/parser/status_parser.rb
@@ -141,7 +141,7 @@ class ActivityPub::Parser::StatusParser
   def quote_subpolicy(subpolicy)
     flags = 0
 
-    allowed_actors = as_array(subpolicy)
+    allowed_actors = as_array(subpolicy).dup
     allowed_actors.uniq!
 
     flags |= Status::QUOTE_APPROVAL_POLICY_FLAGS[:public] if allowed_actors.delete('as:Public') || allowed_actors.delete('Public') || allowed_actors.delete('https://www.w3.org/ns/activitystreams#Public')