diff --git a/5.0-Upgrade.md b/5.0-Upgrade.md
index 12dc058c..9b91116e 100644
--- a/5.0-Upgrade.md
+++ b/5.0-Upgrade.md
@@ -24,7 +24,9 @@ Production testing at GitLab suggests values between `0.001` and `0.010` are bes
 
 5.0 brings two new options to your config which may improve memory usage.
 
-`nakayoshi_fork` calls GC a handful of times and compacts the heap on Ruby 2.7+ before forking. This may reduce memory usage on Pumas on MRI with preload enabled.
+#### nakayoshi_fork
+
+`nakayoshi_fork` calls GC a handful of times and compacts the heap on Ruby 2.7+ before forking. This may reduce memory usage on Pumas on MRI with preload enabled. It's inspired by [Koichi Sasada's work](https://github.com/ko1/nakayoshi_fork).
 
 To use it, you can add this to your `puma.rb`:
 
@@ -32,6 +34,8 @@ To use it, you can add this to your `puma.rb`:
 nakayoshi_fork
 ```
 
+#### fork_worker
+
 Puma 5 introduces an experimental new cluster-mode configuration option, `fork_worker` (`--fork-worker` from the CLI). This mode causes Puma to fork additional workers from worker 0, instead of directly from the master process:
 
 ```