diff --git a/README.md b/README.md
index 2b0a124..85c27c3 100644
--- a/README.md
+++ b/README.md
@@ -31,6 +31,15 @@ sudo nix-channel --update
 
 Then run `nixos-rebuild switch`, see above.
 
+## Garbage Collection
+
+* https://nixos.org/manual/nix/stable/package-management/garbage-collection.html
+
+```shell
+nix-env --delete-generations 14d
+nix-store --gc
+```
+
 ## Install Home Manager with niv
 
 niv: