diff --git a/justfile b/justfile
index e41f3dc..2cafc1a 100644
--- a/justfile
+++ b/justfile
@@ -271,7 +271,29 @@ prek-run-on-all *args: _ensure_mise_tools_installed
 
 # Installs the git pre-commit hook (runs prek automatically before each commit)
 prek-install-git-pre-commit-hook: _ensure_mise_tools_installed
-	@just --justfile {{ justfile() }} mise exec -- prek install
+	#!/usr/bin/env sh
+	set -eu
+	just --justfile {{ justfile() }} mise exec -- prek install
+	# The installed git hooks run later under Git, outside this just/mise environment,
+	# so they need to be told how to find their tooling:
+	#
+	# - MISE_DATA_DIR / MISE_TRUSTED_CONFIG_PATHS make mise resolve against this project's
+	#   own data directory. Without them mise falls back to the global one and silently
+	#   installs a second copy of the tool there.
+	# - prek bakes the full path of the currently installed version into the hook
+	#   (var/mise/installs/prek/<version>/...), which stops working as soon as the pinned
+	#   version changes or old versions are pruned. Pointing at mise's shim instead makes
+	#   the hook resolve whatever mise.toml pins, at the time it runs.
+	#
+	# Which hook files prek installs depends on `default_install_hook_types` in
+	# .pre-commit-config.yaml, so patch every hook file that prek generated.
+	for hook in "{{ justfile_directory() }}"/.git/hooks/*; do
+		[ -f "$hook" ] || continue
+		grep -q 'generated by prek' "$hook" || continue
+		grep -q '^export MISE_DATA_DIR=' "$hook" || sed -i '2iexport MISE_DATA_DIR="{{ mise_data_dir }}"' "$hook"
+		grep -q '^export MISE_TRUSTED_CONFIG_PATHS=' "$hook" || sed -i '3iexport MISE_TRUSTED_CONFIG_PATHS="{{ mise_trusted_config_paths }}"' "$hook"
+		sed -i 's#^PREK=".*"$#PREK="{{ mise_data_dir }}/shims/prek"#' "$hook"
+	done
 
 # Internal - ensures var/mise directory exists
 _ensure_mise_data_directory: