diff --git a/README.md b/README.md
index 5f5069c..a3bb8cd 100644
--- a/README.md
+++ b/README.md
@@ -12,6 +12,25 @@ Directly change to new config, make it default:
 sudo nixos-rebuild -I nixos-config=yodaTux/configuration.nix switch
 ```
 
+## System updates
+
+* https://superuser.com/a/1604695
+
+```shell
+sudo nix-channel --update
+```
+
+```shell
+# The -s param does currently not work for both, .nix and .json file.
+# Workaround: https://github.com/nmattia/niv/pull/133#issuecomment-703322261
+#
+#niv --sources-file=yodaTux/nix/sources.json update
+#
+(cd yodaTux && niv update)
+```
+
+Then run `nixos-rebuild switch`, see above.
+
 ## Install Home Manager with niv
 
 niv:
@@ -49,7 +68,7 @@ sudo nix-channel --list
 Use the corresponding branch:
 
 ```shell
-niv add nix-community/home-manager -n home-manager -b release-23.05
+(cd yodaTux && niv add nix-community/home-manager -n home-manager -b release-23.05)
 ```
 
 ## disko and nixos-anywhere
diff --git a/yodaTux/nix/sources.json b/yodaTux/nix/sources.json
index c787f27..8e9311f 100644
--- a/yodaTux/nix/sources.json
+++ b/yodaTux/nix/sources.json
@@ -17,10 +17,10 @@
         "homepage": null,
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "6c43a3495a11e261e5f41e5d7eda2d71dae1b2fe",
-        "sha256": "16f329z831bq7l3wn1dfvbkh95l2gcggdwn6rk3cisdmv2aa3189",
+        "rev": "d680ded26da5cf104dd2735a51e88d2d8f487b4d",
+        "sha256": "0xczslr40zy1wlg0ir8mwyyn5gz22i2f9dfd0vmgnk1664v4chky",
         "type": "tarball",
-        "url": "https://github.com/NixOS/nixpkgs/archive/6c43a3495a11e261e5f41e5d7eda2d71dae1b2fe.tar.gz",
+        "url": "https://github.com/NixOS/nixpkgs/archive/d680ded26da5cf104dd2735a51e88d2d8f487b4d.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     }
 }