diff --git a/test/web/admin_api/controllers/instance_document_controller_test.exs b/test/web/admin_api/controllers/instance_document_controller_test.exs
new file mode 100644
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+++ b/test/web/admin_api/controllers/instance_document_controller_test.exs
@@ -0,0 +1,106 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2020 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.AdminAPI.InstanceDocumentControllerTest do
+  use Pleroma.Web.ConnCase, async: true
+  import Pleroma.Factory
+  alias Pleroma.Config
+
+  @dir "test/tmp/instance_static"
+  @default_instance_panel ~s(<p>Welcome to <a href="https://pleroma.social" target="_blank">Pleroma!</a></p>)
+
+  setup do
+    File.mkdir_p!(@dir)
+    on_exit(fn -> File.rm_rf(@dir) end)
+  end
+
+  setup do: clear_config([:instance, :static_dir], @dir)
+
+  setup do
+    admin = insert(:user, is_admin: true)
+    token = insert(:oauth_admin_token, user: admin)
+
+    conn =
+      build_conn()
+      |> assign(:user, admin)
+      |> assign(:token, token)
+
+    {:ok, %{admin: admin, token: token, conn: conn}}
+  end
+
+  describe "GET /api/pleroma/admin/instance_document/:name" do
+    test "return the instance document url", %{conn: conn} do
+      conn = get(conn, "/api/pleroma/admin/instance_document/instance-panel")
+
+      assert content = html_response(conn, 200)
+      assert String.contains?(content, @default_instance_panel)
+    end
+
+    test "it returns 403 if requested by a non-admin" do
+      non_admin_user = insert(:user)
+      token = insert(:oauth_token, user: non_admin_user)
+
+      conn =
+        build_conn()
+        |> assign(:user, non_admin_user)
+        |> assign(:token, token)
+        |> get("/api/pleroma/admin/instance_document/instance-panel")
+
+      assert json_response(conn, :forbidden)
+    end
+
+    test "it returns 404 if the instance document with the given name doesn't exist", %{
+      conn: conn
+    } do
+      conn = get(conn, "/api/pleroma/admin/instance_document/1234")
+
+      assert json_response_and_validate_schema(conn, 404)
+    end
+  end
+
+  describe "PATCH /api/pleroma/admin/instance_document/:name" do
+    test "uploads the instance document", %{conn: conn} do
+      image = %Plug.Upload{
+        content_type: "text/html",
+        path: Path.absname("test/fixtures/custom_instance_panel.html"),
+        filename: "custom_instance_panel.html"
+      }
+
+      conn =
+        conn
+        |> put_req_header("content-type", "multipart/form-data")
+        |> patch("/api/pleroma/admin/instance_document/instance-panel", %{
+          "file" => image
+        })
+
+      assert %{"url" => url} = json_response_and_validate_schema(conn, 200)
+      index = get(build_conn(), url)
+      assert html_response(index, 200) == "<h2>Custom instance panel</h2>"
+    end
+  end
+
+  describe "DELETE /api/pleroma/admin/instance_document/:name" do
+    test "deletes the instance document", %{conn: conn} do
+      File.mkdir!(@dir <> "/instance/")
+      File.write!(@dir <> "/instance/panel.html", "Custom instance panel")
+
+      conn_resp =
+        conn
+        |> get("/api/pleroma/admin/instance_document/instance-panel")
+
+      assert html_response(conn_resp, 200) == "Custom instance panel"
+
+      conn
+      |> delete("/api/pleroma/admin/instance_document/instance-panel")
+      |> json_response_and_validate_schema(200)
+
+      conn_resp =
+        conn
+        |> get("/api/pleroma/admin/instance_document/instance-panel")
+
+      assert content = html_response(conn_resp, 200)
+      assert String.contains?(content, @default_instance_panel)
+    end
+  end
+end