diff --git a/README.rst b/README.rst
index 4ca9625..5667425 100644
--- a/README.rst
+++ b/README.rst
@@ -31,7 +31,7 @@ Dependency
 
   * tornado + pycurl
   * aiohttp
-  * httpx with http2 support
+  * httpx with http2 support (experimental; only latest version is supported)
   * tornado
 
 - All commands used in your software version configuration files
diff --git a/docs/usage.rst b/docs/usage.rst
index 2ac14dc..d0fdf86 100644
--- a/docs/usage.rst
+++ b/docs/usage.rst
@@ -25,7 +25,7 @@ Dependency
 
   * tornado + pycurl
   * aiohttp
-  * httpx with http2 support
+  * httpx with http2 support (experimental; only latest version is supported)
   * tornado
 
 - All commands used in your software version configuration files
diff --git a/nvchecker/httpclient/httpx_httpclient.py b/nvchecker/httpclient/httpx_httpclient.py
index b1161a4..7c78b1d 100644
--- a/nvchecker/httpclient/httpx_httpclient.py
+++ b/nvchecker/httpclient/httpx_httpclient.py
@@ -25,7 +25,7 @@ class HttpxSession(BaseSession):
     client = self.clients.get(proxy)
     if not client:
       client = httpx.AsyncClient(
-        timeout = httpx.Timeout(20, pool_timeout=None),
+        timeout = httpx.Timeout(20, pool=None),
         http2 = True,
         proxies = {'all://': proxy},
       )