diff --git a/zsh/do-not-overwrite-existing-files.md b/zsh/do-not-overwrite-existing-files.md
index d7b2740..ed7175f 100644
--- a/zsh/do-not-overwrite-existing-files.md
+++ b/zsh/do-not-overwrite-existing-files.md
@@ -2,3 +2,5 @@
 
 When using the `cp` command to copy files, you can use the `-n` flag to make
 sure that you do not overwrite existing files.
+
+h/t [Dillon Hafer](https://twitter.com/dillonhafer)