diff --git a/lib/nulla/activitypub.ex b/lib/nulla/activitypub.ex
index 838aae4..0f7dd73 100644
--- a/lib/nulla/activitypub.ex
+++ b/lib/nulla/activitypub.ex
@@ -209,7 +209,7 @@ defmodule Nulla.ActivityPub do
 
   @spec webfinger(Actor.t()) :: Jason.OrderedObject.t()
   def webfinger(actor) do
-    Jason.OrderedObject.new(
+    data = [
       subject: "#{actor.preferredUsername}@#{actor.domain}",
       aliases: [
         "https://#{actor.domain}/@#{actor.preferredUsername}",
@@ -225,14 +225,27 @@ defmodule Nulla.ActivityPub do
           rel: "self",
           type: "application/activity+json",
           href: "https://#{actor.domain}/users/#{actor.preferredUsername}"
-        ),
-        Jason.OrderedObject.new(
-          rel: "http://webfinger.net/rel/avatar",
-          type: actor.icon.mediaType,
-          href: actor.icon.url
         )
       ]
-    )
+    ]
+
+    data =
+      if actor.icon do
+        Keyword.update!(data, :links, fn links ->
+          links ++
+            [
+              Jason.OrderedObject.new(
+                rel: "http://webfinger.net/rel/avatar",
+                type: Map.get(actor.icon, :mediaType),
+                href: Map.get(actor.icon, :url)
+              )
+            ]
+        end)
+      else
+        data
+      end
+
+    Jason.OrderedObject.new(data)
   end
 
   @spec nodeinfo(String.t()) :: Jason.OrderedObject.t()
diff --git a/lib/nulla/models/actor.ex b/lib/nulla/models/actor.ex
index f1c58a1..d77fcb0 100644
--- a/lib/nulla/models/actor.ex
+++ b/lib/nulla/models/actor.ex
@@ -29,8 +29,8 @@ defmodule Nulla.Models.Actor do
     field :tag, {:array, :map}, default: []
     field :attachment, {:array, :map}, default: []
     field :endpoints, :map
-    field :icon, :map, default: %{}
-    field :image, :map, default: %{}
+    field :icon, :map
+    field :image, :map
     field :vcard_bday, :date
     field :vcard_Address, :string
 
diff --git a/lib/nulla_web/controllers/webfinger_controller.ex b/lib/nulla_web/controllers/webfinger_controller.ex
index cc7854f..a36e6b3 100644
--- a/lib/nulla_web/controllers/webfinger_controller.ex
+++ b/lib/nulla_web/controllers/webfinger_controller.ex
@@ -5,13 +5,13 @@ defmodule NullaWeb.WebfingerController do
   alias Nulla.Models.InstanceSettings
 
   def index(conn, %{"resource" => resource}) do
-    case Regex.run(~r/^acct:([^@]+)@(.+)$/, resource) do
+    case Regex.run(~r/^acct:(.+)@(.+)$/, resource) do
       [_, username, domain] ->
         case Actor.get_actor(username, domain) do
           nil ->
             conn
-            |> put_status(:not_found)
-            |> json(%{error: "Not Found"})
+            |> put_resp_content_type("text/plain")
+            |> send_resp(404, "")
 
           %Actor{} = actor ->
             instance_settings = InstanceSettings.get_instance_settings!()
@@ -20,15 +20,21 @@ defmodule NullaWeb.WebfingerController do
               json(conn, ActivityPub.webfinger(actor))
             else
               conn
-              |> put_status(:not_found)
-              |> json(%{error: "Not Found"})
+              |> put_resp_content_type("text/plain")
+              |> send_resp(404, "")
             end
         end
 
       _ ->
         conn
-        |> put_status(:bad_request)
-        |> json(%{error: "Bad Request"})
+        |> put_resp_content_type("text/plain")
+        |> send_resp(400, "")
     end
   end
+
+  def index(conn, _params) do
+    conn
+    |> put_resp_content_type("text/plain")
+    |> send_resp(400, "")
+  end
 end
diff --git a/priv/repo/migrations/20250615130714_create_actors.exs b/priv/repo/migrations/20250615130714_create_actors.exs
index da2ff37..8098ce9 100644
--- a/priv/repo/migrations/20250615130714_create_actors.exs
+++ b/priv/repo/migrations/20250615130714_create_actors.exs
@@ -26,8 +26,8 @@ defmodule Nulla.Repo.Migrations.CreateActors do
       add :tag, {:array, :map}, default: []
       add :attachment, {:array, :map}, default: []
       add :endpoints, :map
-      add :icon, :map, default: %{}
-      add :image, :map, default: %{}
+      add :icon, :map
+      add :image, :map
       add :vcard_bday, :date
       add :vcard_Address, :string
     end