diff --git a/pre_commit/languages/julia.py b/pre_commit/languages/julia.py
index 3e74d427..6d70edd9 100644
--- a/pre_commit/languages/julia.py
+++ b/pre_commit/languages/julia.py
@@ -5,11 +5,14 @@ import os
 import shutil
 from collections.abc import Generator
 from collections.abc import Sequence
+from typing import Union
 
 from pre_commit import lang_base
+from pre_commit.envcontext import _Unset
 from pre_commit.envcontext import envcontext
 from pre_commit.envcontext import PatchesT
 from pre_commit.envcontext import UNSET
+from pre_commit.envcontext import Var
 from pre_commit.prefix import Prefix
 from pre_commit.util import cmd_output_b
 
@@ -46,8 +49,11 @@ def run_hook(
     )
 
 
+PatchEntry = tuple[str, Union[str, _Unset, tuple[Union[str, Var], ...]]]
+
+
 def get_env_patch(target_dir: str, version: str) -> PatchesT:
-    patches = [
+    patches: list[PatchEntry] = [
         ('JULIA_LOAD_PATH', target_dir),
         ('JULIA_PROJECT', UNSET),
     ]
@@ -130,6 +136,6 @@ def install_environment(
         end
         """
         cmd_output_b(
-            'julia', '--startup-file=no', '-e', julia_code, '--', envdir, *additional_dependencies,
-            cwd=prefix.prefix_dir,
+            'julia', '--startup-file=no', '-e', julia_code, '--', envdir,
+            *additional_dependencies, cwd=prefix.prefix_dir,
         )