diff --git a/README.md b/README.md
index 937e29e..fd858f1 100644
--- a/README.md
+++ b/README.md
@@ -141,7 +141,7 @@ You can also use the [vim-tab-bar](https://github.com/jamescherti/vim-tab-bar.el
 
 ### Automatically compile Emacs Lisp libraries
 
-Add the following to the beginning of `~/.emacs.d/pre-init.el`, before all other `use-package` statements:
+Add the following to the beginning of `~/.emacs.d/post-init.el`, before all other `use-package` statements:
 ``` emacs-lisp
 (use-package auto-compile
   :ensure t
@@ -154,6 +154,15 @@ Add the following to the beginning of `~/.emacs.d/pre-init.el`, before all other
 
 (`auto-compile` provides two minor modes which automatically recompile Emacs Lisp source files. Together these modes guarantee that Emacs never loads outdated byte code files.)
 
+### how to activate gcmh?
+
+Add the following to the beginning of `~/.emacs.d/post-init.el`, before all other `use-package` statements:
+``` emacs-lisp
+(use-package gcmh
+  :ensure t
+  :hook ((emacs-startup . gcmh-mode)))
+```
+
 ### How to configure straight.el?
 
 [Add the straight.el bootstrap code](https://github.com/radian-software/straight.el?tab=readme-ov-file#getting-started) to `~/.emacs.d/pre-init.el`: