From 24a55d73c31475f3d17ee46580810bc30efc369b Mon Sep 17 00:00:00 2001
From: Marat Sharafutdinov <decaz89@gmail.com>
Date: Wed, 10 Mar 2021 12:49:37 +0300
Subject: [PATCH] Fix CertTypes (#1503)

---
 httpx/_types.py | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/httpx/_types.py b/httpx/_types.py
index 7768bac1..385f89dd 100644
--- a/httpx/_types.py
+++ b/httpx/_types.py
@@ -51,7 +51,14 @@ HeaderTypes = Union[
 
 CookieTypes = Union["Cookies", CookieJar, Dict[str, str], List[Tuple[str, str]]]
 
-CertTypes = Union[str, Tuple[str, str], Tuple[str, str, str]]
+CertTypes = Union[
+    # certfile
+    str,
+    # (certfile, keyfile)
+    Tuple[str, Optional[str]],
+    # (certfile, keyfile, password)
+    Tuple[str, Optional[str], Optional[str]],
+]
 VerifyTypes = Union[str, bool, ssl.SSLContext]
 TimeoutTypes = Union[
     Optional[float],