diff --git a/.profile b/.profile
index cc12d25..ff7b295 100644
--- a/.profile
+++ b/.profile
@@ -1,3 +1,4 @@
+# https://tratt.net/laurie/blog/2024/faster_shell_startup_with_shell_switching.html
 if [[ $- == *"i"* ]]; then
   exec zsh
 fi