diff --git a/changelog.d/video-thumbs.fix b/changelog.d/video-thumbs.fix
new file mode 100644
index 000000000..03e862f3d
--- /dev/null
+++ b/changelog.d/video-thumbs.fix
@@ -0,0 +1 @@
+Video thumbnails were not being generated due to a negative cache lookup logic error
diff --git a/lib/pleroma/helpers/media_helper.ex b/lib/pleroma/helpers/media_helper.ex
index 0ac07fa41..8566ab3ea 100644
--- a/lib/pleroma/helpers/media_helper.ex
+++ b/lib/pleroma/helpers/media_helper.ex
@@ -45,7 +45,7 @@ def image_resize(url, options) do
   @spec video_framegrab(String.t()) :: {:ok, binary()} | {:error, any()}
   def video_framegrab(url) do
     with executable when is_binary(executable) <- System.find_executable("ffmpeg"),
-         false <- @cachex.exists?(:failed_media_helper_cache, url),
+         {:ok, false} <- @cachex.exists?(:failed_media_helper_cache, url),
          {:ok, env} <- HTTP.get(url, [], http_client_opts()),
          {:ok, pid} <- StringIO.open(env.body) do
       body_stream = IO.binstream(pid, 1)
@@ -71,13 +71,13 @@ def video_framegrab(url) do
         end)
 
       case Task.yield(task, 5_000) do
-        nil ->
+        {:ok, result} ->
+          {:ok, result}
+
+        _ ->
           Task.shutdown(task)
           @cachex.put(:failed_media_helper_cache, url, nil)
           {:error, {:ffmpeg, :timeout}}
-
-        result ->
-          {:ok, result}
       end
     else
       nil -> {:error, {:ffmpeg, :command_not_found}}