diff --git a/microvenv/__init__.pyi b/microvenv/__init__.pyi
index ff251e7..5612712 100644
--- a/microvenv/__init__.pyi
+++ b/microvenv/__init__.pyi
@@ -1,4 +1,4 @@
-from os import PathLike
+from os import PathLike, _Environ
 from typing import TypedDict
 
 IN_VIRTUAL_ENV: bool
@@ -13,4 +13,4 @@ class _ActivationEnvVars(TypedDict):
     PATH: str
     VIRTUAL_ENV: str
 
-def activation(env_vars: dict[str, str] = ...) -> _ActivationEnvVars: ...
+def activation(env_vars: _Environ[str] = ...) -> _ActivationEnvVars: ...
diff --git a/microvenv/_create.pyi b/microvenv/_create.pyi
index a4ff8bc..fa1b966 100644
--- a/microvenv/_create.pyi
+++ b/microvenv/_create.pyi
@@ -1,6 +1,8 @@
 from os import PathLike
 from typing import Iterable
 
+DEFAULT_ENV_DIR: str
+
 def create(
     env_dir: str | PathLike[str] = ..., *, scm_ignore_files=Iterable[str]
 ) -> None: ...
diff --git a/noxfile.py b/noxfile.py
index ad48af5..7a41bed 100644
--- a/noxfile.py
+++ b/noxfile.py
@@ -16,6 +16,7 @@ def lint(session):
     session.run("ruff", "check", ".")
     session.run("black", "--check", ".")
     session.run("mypy", ".")
+    session.run("stubtest", "microvenv")
 
 
 @nox.session