diff --git a/pyproject.toml b/pyproject.toml
index c63c46452e..d085811107 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -44,6 +44,7 @@ Repository = "https://github.com/openai/openai-python"
 
 [project.optional-dependencies]
 aiohttp = ["aiohttp", "httpx_aiohttp>=0.1.9"]
+http2 = ["httpx[http2]"]
 realtime = ["websockets >= 13, < 16"]
 datalib = ["numpy >= 1", "pandas >= 1.2.3", "pandas-stubs >= 1.1.0.11"]
 voice_helpers = ["sounddevice>=0.5.1", "numpy>=2.0.2"]
diff --git a/src/openai/_base_client.py b/src/openai/_base_client.py
index 216b36aabd..60d997caa0 100644
--- a/src/openai/_base_client.py
+++ b/src/openai/_base_client.py
@@ -39,6 +39,13 @@
 from httpx import URL
 from pydantic import PrivateAttr
 
+try:
+    import h2  # noqa: F401
+
+    _HTTP2_AVAILABLE = True
+except ImportError:
+    _HTTP2_AVAILABLE = False
+
 from . import _exceptions
 from ._qs import Querystring
 from ._files import to_httpx_files, async_to_httpx_files
@@ -836,6 +843,7 @@ def __init__(self, **kwargs: Any) -> None:
         kwargs.setdefault("timeout", DEFAULT_TIMEOUT)
         kwargs.setdefault("limits", DEFAULT_CONNECTION_LIMITS)
         kwargs.setdefault("follow_redirects", True)
+        kwargs.setdefault("http2", _HTTP2_AVAILABLE)
         super().__init__(**kwargs)
 
 
@@ -1423,6 +1431,7 @@ def __init__(self, **kwargs: Any) -> None:
         kwargs.setdefault("timeout", DEFAULT_TIMEOUT)
         kwargs.setdefault("limits", DEFAULT_CONNECTION_LIMITS)
         kwargs.setdefault("follow_redirects", True)
+        kwargs.setdefault("http2", _HTTP2_AVAILABLE)
         super().__init__(**kwargs)