diff --git a/lib/pinchflat/yt_dlp/download_option_builder.ex b/lib/pinchflat/yt_dlp/download_option_builder.ex
index d786123..c53b731 100644
--- a/lib/pinchflat/yt_dlp/download_option_builder.ex
+++ b/lib/pinchflat/yt_dlp/download_option_builder.ex
@@ -63,7 +63,7 @@ defmodule Pinchflat.YtDlp.DownloadOptionBuilder do
     Enum.reduce(mapped_struct, [], fn attr, acc ->
       case {attr, media_profile} do
         {{:download_thumbnail, true}, _} ->
-          acc ++ [:write_thumbnail]
+          acc ++ [:write_thumbnail, convert_thumbnail: "jpg"]
 
         {{:embed_thumbnail, true}, %{preferred_resolution: pr}} when pr != :audio ->
           acc ++ [:embed_thumbnail]
diff --git a/test/pinchflat/yt_dlp/download_option_builder_test.exs b/test/pinchflat/yt_dlp/download_option_builder_test.exs
index 58c7e18..c17ff54 100644
--- a/test/pinchflat/yt_dlp/download_option_builder_test.exs
+++ b/test/pinchflat/yt_dlp/download_option_builder_test.exs
@@ -125,6 +125,14 @@ defmodule Pinchflat.YtDlp.DownloadOptionBuilderTest do
       assert :write_thumbnail in res
     end
 
+    test "convertes thumbnail to jpg when download_thumbnail is true", %{media_item: media_item} do
+      media_item = update_media_profile_attribute(media_item, %{download_thumbnail: true})
+
+      assert {:ok, res} = DownloadOptionBuilder.build(media_item)
+
+      assert {:convert_thumbnail, "jpg"} in res
+    end
+
     test "includes :embed_thumbnail option when specified", %{media_item: media_item} do
       media_item = update_media_profile_attribute(media_item, %{embed_thumbnail: true})