diff --git a/CODE_GUIDELINES.md b/CODE_GUIDELINES.md
index 2b378ef..ccd16f4 100644
--- a/CODE_GUIDELINES.md
+++ b/CODE_GUIDELINES.md
@@ -1363,6 +1363,8 @@ mix gettext.merge priv/gettext --on-obsolete=mark_as_obsolete
 
 ### 3.13 Task Runner: Just
 
+The `Justfile` prepends `~/.asdf/shims`, `~/.asdf/bin`, and `~/.asdf` to `PATH` for all recipes (`set export := true`), so `mix` / `elixir` resolve from `.tool-versions` without shell init. The caller's `PATH` is kept (e.g. Homebrew `asdf`, Docker). Run `asdf install` once per machine; no extra `source` is required for `just run`.
+
 **Common Commands:**
 
 ```bash
diff --git a/Justfile b/Justfile
index d08cef8..9b0be65 100644
--- a/Justfile
+++ b/Justfile
@@ -1,11 +1,11 @@
 set dotenv-load := true
 set export := true
 
-# Non-interactive shells do not source .bashrc,
-# PATH includes asdf shims so that mix / elixir / iex resolve without per-shell
-# `source ~/.asdf/asdf.sh`. Recipes inherit this via `set export := true`.
-home := env_var('HOME')
-PATH := home + "/.asdf/shims:" + home + "/.asdf:" + home + "/.local/bin:/usr/local/bin:/usr/bin:/bin"
+# Prepend asdf paths so recipes work without sourcing ~/.asdf/asdf.sh in the shell.
+# Caller PATH is preserved (Homebrew asdf, docker CLI, etc.). See CODE_GUIDELINES §3.13.
+home := env_var("HOME")
+asdf_paths := home + "/.asdf/shims:" + home + "/.asdf/bin:" + home + "/.asdf:"
+PATH := asdf_paths + env_var("PATH")
 
 MIX_QUIET := "1"