diff --git a/README.md b/README.md
index c2d130e1..ec47e1eb 100644
--- a/README.md
+++ b/README.md
@@ -32,6 +32,7 @@ git add ./hosts/${new_host}.nix
 
 # You can specify any of the host configurations living in the ./hosts
 # directory. If omitted, it will default to your systems current hostname.
+# This will be run as root.
 rebuild $new_host switch
 
 ```
diff --git a/shell.nix b/shell.nix
index 95264c12..a8af3c79 100644
--- a/shell.nix
+++ b/shell.nix
@@ -10,9 +10,9 @@ let
     elif [[ $1 == "iso" ]]; then
       nix build ${configs}.niximg.${build}.isoImage
     elif [[ -z $2 ]]; then
-      nix run -vv ${configs}.${hostname}.${build}.toplevel -c switch-to-configuration $1
+      sudo -E nix run -vv ${configs}.${hostname}.${build}.toplevel -c switch-to-configuration $1
     else
-      nix run -vv ${configs}.$1.${build}.toplevel -c switch-to-configuration $2
+      sudo -E nix run -vv ${configs}.$1.${build}.toplevel -c switch-to-configuration $2
     fi
   '';
 in pkgs.mkShell {