diff --git a/.envrc b/.envrc
new file mode 100644
index 0000000..f688e49
--- /dev/null
+++ b/.envrc
@@ -0,0 +1,5 @@
+use flake
+
+# devshell needs the shellHook to run even when cached
+# https://github.com/nix-community/nix-direnv/issues/109
+eval "$shellHook"
diff --git a/.gitignore b/.gitignore
index 6f2bad1..289bb02 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,3 +1,4 @@
+.direnv
 result*
 /.vms/*
 !/.vms/.gitkeep
diff --git a/homes/castle.nix b/homes/castle.nix
index a4d6bdd..967a2b5 100644
--- a/homes/castle.nix
+++ b/homes/castle.nix
@@ -1,5 +1,8 @@
 { pkgs, ... }:
 {
+  # So home-manager will inject the sourcing of ~/.nix-profile/etc/profile.d/nix.sh
+  targets.genericLinux.enable = true;
+
   programs = {
     kakoune.enable = true;
   };