diff --git a/test/pleroma/web/plugs/favicon_plug_test.exs b/test/pleroma/web/plugs/favicon_plug_test.exs
new file mode 100644
index 000000000..36650e7bf
--- /dev/null
+++ b/test/pleroma/web/plugs/favicon_plug_test.exs
@@ -0,0 +1,69 @@
+# Pleroma: A lightweight social networking server
+# Copyright © 2017-2026 Pleroma Authors <https://pleroma.social/>
+# SPDX-License-Identifier: AGPL-3.0-only
+
+defmodule Pleroma.Web.Plugs.FaviconPlugTest do
+  use Pleroma.Web.ConnCase
+
+  # import Mox
+
+  # alias Pleroma.UnstubbedConfigMock, as: ConfigMock
+
+  @dir "test/tmp/favicon_static"
+
+  describe "default favicon" do
+    test "returns favicon", %{conn: conn} do
+      conn = get(conn, "/favicon.png")
+      etag = get_resp_header(conn, "etag")
+
+      # etag changes when serving a different file
+      assert etag == ["\"72487CE\""]
+      assert response_content_type(conn, :png)
+    end
+
+    test "returns correct cache-control", %{conn: conn} do
+      cache = 
+        conn
+        |> get("/favicon.png")
+        |> get_resp_header("cache-control")
+
+      assert cache == ["public, max=age=86400, immutable"]
+    end
+  end
+
+  describe "custom favicon" do
+    setup do
+      Pleroma.Backports.mkdir_p!(@dir)
+      favicon_path = Path.join(@dir, "favicon.png")
+
+      # Favicon plug should always return image/png
+      donor_image = "test/fixtures/image.gif"
+      image_stat = File.stat!(donor_image)
+
+      # Preserve stat since that's what etag is based on
+      File.cp!(donor_image, favicon_path)
+      File.write_stat!(favicon_path, image_stat)
+
+      clear_config([:instance, :static_dir], @dir)
+
+      on_exit( fn -> File.rm_rf!(@dir) end)
+    end
+
+    test "returns favicon", %{conn: conn} do
+      conn = get(conn, "/favicon.png")
+      etag = get_resp_header(conn, "etag")
+
+      assert etag == ["\"215A3A4\""]
+      assert response_content_type(conn, :png)
+    end
+
+    test "returns correct cache-control", %{conn: conn} do
+      cache =
+       conn
+       |> get("/favicon.png")
+       |> get_resp_header("cache-control")
+
+      assert cache == ["public, max=age=86400, immutable"]
+    end
+  end
+end