From cb309b3293c9919cfb55f5d9ffa2c8c109a5f1eb Mon Sep 17 00:00:00 2001
From: doe1080 <98906116+doe1080@users.noreply.github.com>
Date: Thu, 11 Jun 2026 23:43:24 +0900
Subject: [PATCH] [utils] `HTTPHeaderDict`: Fix `__ior__` (#16930)

Authored by: doe1080
---
 test/test_utils.py         | 4 ++++
 yt_dlp/utils/networking.py | 2 +-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/test/test_utils.py b/test/test_utils.py
index cd0fb0f2e9..8f86d151b2 100644
--- a/test/test_utils.py
+++ b/test/test_utils.py
@@ -2172,6 +2172,10 @@ Line 1
         headers6 = HTTPHeaderDict(a=1, b=2)
         self.assertEqual(pickle.loads(pickle.dumps(headers6)), headers6)
 
+        headers7 = HTTPHeaderDict()
+        headers7 |= {'X-dlp': 'data'}
+        self.assertEqual(headers7.sensitive(), {'X-dlp': 'data'})
+
     def test_extract_basic_auth(self):
         assert extract_basic_auth('http://:foo.bar') == ('http://:foo.bar', None)
         assert extract_basic_auth('http://foo.bar') == ('http://foo.bar', None)
diff --git a/yt_dlp/utils/networking.py b/yt_dlp/utils/networking.py
index 32c7acdb14..33cca412dc 100644
--- a/yt_dlp/utils/networking.py
+++ b/yt_dlp/utils/networking.py
@@ -64,7 +64,7 @@ class HTTPHeaderDict(dict):
             other = other.sensitive()
         if isinstance(other, dict):
             self.update(other)
-            return
+            return self
         return NotImplemented
 
     def __or__(self, other, /) -> typing.Self: