diff --git a/lib/pleroma/web/activity_pub/object_validators/answer_validator.ex b/lib/pleroma/web/activity_pub/object_validators/answer_validator.ex
index 323367642..b9fbaf4f6 100644
--- a/lib/pleroma/web/activity_pub/object_validators/answer_validator.ex
+++ b/lib/pleroma/web/activity_pub/object_validators/answer_validator.ex
@@ -15,16 +15,13 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.AnswerValidator do
 
   embedded_schema do
     field(:id, ObjectValidators.ObjectID, primary_key: true)
-    field(:to, {:array, :string}, default: [])
-    field(:cc, {:array, :string}, default: [])
-
-    # is this actually needed?
-    field(:bto, {:array, :string}, default: [])
-    field(:bcc, {:array, :string}, default: [])
-
+    field(:to, ObjectValidators.Recipients, default: [])
+    field(:cc, ObjectValidators.Recipients, default: [])
+    field(:bto, ObjectValidators.Recipients, default: [])
+    field(:bcc, ObjectValidators.Recipients, default: [])
     field(:type, :string)
     field(:name, :string)
-    field(:inReplyTo, :string)
+    field(:inReplyTo, ObjectValidators.ObjectID)
     field(:attributedTo, ObjectValidators.ObjectID)
 
     # TODO: Remove actor on objects
diff --git a/lib/pleroma/web/activity_pub/object_validators/create_note_validator.ex b/lib/pleroma/web/activity_pub/object_validators/create_note_validator.ex
index 316bd0c07..9b9743c4a 100644
--- a/lib/pleroma/web/activity_pub/object_validators/create_note_validator.ex
+++ b/lib/pleroma/web/activity_pub/object_validators/create_note_validator.ex
@@ -16,11 +16,10 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.CreateNoteValidator do
     field(:id, ObjectValidators.ObjectID, primary_key: true)
     field(:actor, ObjectValidators.ObjectID)
     field(:type, :string)
-    field(:to, {:array, :string})
-    field(:cc, {:array, :string})
-    field(:bto, {:array, :string}, default: [])
-    field(:bcc, {:array, :string}, default: [])
-
+    field(:to, ObjectValidators.Recipients, default: [])
+    field(:cc, ObjectValidators.Recipients, default: [])
+    field(:bto, ObjectValidators.Recipients, default: [])
+    field(:bcc, ObjectValidators.Recipients, default: [])
     embeds_one(:object, NoteValidator)
   end
 
diff --git a/lib/pleroma/web/activity_pub/object_validators/emoji_react_validator.ex b/lib/pleroma/web/activity_pub/object_validators/emoji_react_validator.ex
index a543af1f8..336c92d35 100644
--- a/lib/pleroma/web/activity_pub/object_validators/emoji_react_validator.ex
+++ b/lib/pleroma/web/activity_pub/object_validators/emoji_react_validator.ex
@@ -20,8 +20,8 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.EmojiReactValidator do
     field(:actor, ObjectValidators.ObjectID)
     field(:context, :string)
     field(:content, :string)
-    field(:to, {:array, :string}, default: [])
-    field(:cc, {:array, :string}, default: [])
+    field(:to, ObjectValidators.Recipients, default: [])
+    field(:cc, ObjectValidators.Recipients, default: [])
   end
 
   def cast_and_validate(data) do
diff --git a/lib/pleroma/web/activity_pub/object_validators/note_validator.ex b/lib/pleroma/web/activity_pub/object_validators/note_validator.ex
index a65fe2354..14ae29cb6 100644
--- a/lib/pleroma/web/activity_pub/object_validators/note_validator.ex
+++ b/lib/pleroma/web/activity_pub/object_validators/note_validator.ex
@@ -13,10 +13,10 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.NoteValidator do
 
   embedded_schema do
     field(:id, ObjectValidators.ObjectID, primary_key: true)
-    field(:to, {:array, :string}, default: [])
-    field(:cc, {:array, :string}, default: [])
-    field(:bto, {:array, :string}, default: [])
-    field(:bcc, {:array, :string}, default: [])
+    field(:to, ObjectValidators.Recipients, default: [])
+    field(:cc, ObjectValidators.Recipients, default: [])
+    field(:bto, ObjectValidators.Recipients, default: [])
+    field(:bcc, ObjectValidators.Recipients, default: [])
     # TODO: Write type
     field(:tag, {:array, :map}, default: [])
     field(:type, :string)
@@ -34,7 +34,7 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.NoteValidator do
     field(:replies_count, :integer, default: 0)
     field(:like_count, :integer, default: 0)
     field(:announcement_count, :integer, default: 0)
-    field(:inReplyTo, :string)
+    field(:inReplyTo, ObjectValidators.ObjectID)
     field(:uri, ObjectValidators.Uri)
 
     field(:likes, {:array, :string}, default: [])
diff --git a/lib/pleroma/web/activity_pub/object_validators/question_validator.ex b/lib/pleroma/web/activity_pub/object_validators/question_validator.ex
index f47acf606..220065fd4 100644
--- a/lib/pleroma/web/activity_pub/object_validators/question_validator.ex
+++ b/lib/pleroma/web/activity_pub/object_validators/question_validator.ex
@@ -19,10 +19,10 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.QuestionValidator do
   # Extends from NoteValidator
   embedded_schema do
     field(:id, ObjectValidators.ObjectID, primary_key: true)
-    field(:to, {:array, :string}, default: [])
-    field(:cc, {:array, :string}, default: [])
-    field(:bto, {:array, :string}, default: [])
-    field(:bcc, {:array, :string}, default: [])
+    field(:to, ObjectValidators.Recipients, default: [])
+    field(:cc, ObjectValidators.Recipients, default: [])
+    field(:bto, ObjectValidators.Recipients, default: [])
+    field(:bcc, ObjectValidators.Recipients, default: [])
     # TODO: Write type
     field(:tag, {:array, :map}, default: [])
     field(:type, :string)
@@ -42,7 +42,7 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.QuestionValidator do
     field(:replies_count, :integer, default: 0)
     field(:like_count, :integer, default: 0)
     field(:announcement_count, :integer, default: 0)
-    field(:inReplyTo, :string)
+    field(:inReplyTo, ObjectValidators.ObjectID)
     field(:uri, ObjectValidators.Uri)
     # short identifier for PleromaFE to group statuses by context
     field(:context_id, :integer)
@@ -117,7 +117,7 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.QuestionValidator do
   def validate_data(data_cng) do
     data_cng
     |> validate_inclusion(:type, ["Question"])
-    |> validate_required([:id, :actor, :attributedTo, :type, :context])
+    |> validate_required([:id, :actor, :attributedTo, :type, :context, :context_id])
     |> CommonValidations.validate_any_presence([:cc, :to])
     |> CommonValidations.validate_fields_match([:actor, :attributedTo])
     |> CommonValidations.validate_actor_presence()
diff --git a/lib/pleroma/web/activity_pub/object_validators/undo_validator.ex b/lib/pleroma/web/activity_pub/object_validators/undo_validator.ex
index e8d2d39c1..8cae94467 100644
--- a/lib/pleroma/web/activity_pub/object_validators/undo_validator.ex
+++ b/lib/pleroma/web/activity_pub/object_validators/undo_validator.ex
@@ -18,8 +18,8 @@ defmodule Pleroma.Web.ActivityPub.ObjectValidators.UndoValidator do
     field(:type, :string)
     field(:object, ObjectValidators.ObjectID)
     field(:actor, ObjectValidators.ObjectID)
-    field(:to, {:array, :string}, default: [])
-    field(:cc, {:array, :string}, default: [])
+    field(:to, ObjectValidators.Recipients, default: [])
+    field(:cc, ObjectValidators.Recipients, default: [])
   end
 
   def cast_and_validate(data) do