diff --git a/CHANGELOG.md b/CHANGELOG.md
index e8a2ff86..379ddd7f 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,9 @@
 # Changelog
 
+## Unreleased
+
+- Move `typing_extensions` from requirements.txt to pyproject.toml. (#161)
+
 ## 0.0.21 (29th December, 2023)
 
 - Fix inner transport and connection pool instances closing. (#147)
diff --git a/pyproject.toml b/pyproject.toml
index 75cb79f4..f31d1d64 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -29,7 +29,8 @@ classifiers = [
     "Topic :: Internet :: WWW/HTTP",
 ]
 dependencies = [
-    "httpx>=0.22.0"
+    "httpx>=0.22.0",
+    "typing_extensions>=4.8.0"
 ]
 
 [project.optional-dependencies]
diff --git a/requirements.txt b/requirements.txt
index 12a5b4d1..ef1df238 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -16,7 +16,6 @@ anyio==4.1.0
 trio==0.23.1
 coverage==7.3.2
 types-PyYAML==6.0.12.12
-typing_extensions==4.8.0
 
 # build
 hatch==1.7.0