diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index b5ea4de57..972c11e34 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "0.252.0"
+  ".": "0.252.1"
 }
\ No newline at end of file
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0428e6ec2..807c67647 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,13 @@
 # Changelog
 
+## 0.252.1 (2025-06-16)
+
+Full Changelog: [v0.252.0...v0.252.1](https://github.com/Increase/increase-python/compare/v0.252.0...v0.252.1)
+
+### Chores
+
+* **tests:** add tests for httpx client instantiation & proxies ([c021210](https://github.com/Increase/increase-python/commit/c0212102edb6286ac4563a65c3c7ebbe60284499))
+
 ## 0.252.0 (2025-06-13)
 
 Full Changelog: [v0.251.1...v0.252.0](https://github.com/Increase/increase-python/compare/v0.251.1...v0.252.0)
diff --git a/pyproject.toml b/pyproject.toml
index 52c017dd7..6eb3a9c39 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "increase"
-version = "0.252.0"
+version = "0.252.1"
 description = "The official Python library for the increase API"
 dynamic = ["readme"]
 license = "Apache-2.0"
diff --git a/src/increase/_version.py b/src/increase/_version.py
index aa591b4c1..9629d18cb 100644
--- a/src/increase/_version.py
+++ b/src/increase/_version.py
@@ -1,4 +1,4 @@
 # File generated from our OpenAPI spec by Stainless. See CONTRIBUTING.md for details.
 
 __title__ = "increase"
-__version__ = "0.252.0"  # x-release-please-version
+__version__ = "0.252.1"  # x-release-please-version
diff --git a/tests/test_client.py b/tests/test_client.py
index fcc93f9ab..8d6ad45fc 100644
--- a/tests/test_client.py
+++ b/tests/test_client.py
@@ -31,6 +31,8 @@
     DEFAULT_TIMEOUT,
     HTTPX_DEFAULT_TIMEOUT,
     BaseClient,
+    DefaultHttpxClient,
+    DefaultAsyncHttpxClient,
     make_request_options,
 )
 from increase.types.account_create_params import AccountCreateParams
@@ -883,6 +885,28 @@ def retry_handler(_request: httpx.Request) -> httpx.Response:
 
         assert response.http_request.headers.get("x-stainless-retry-count") == "42"
 
+    def test_proxy_environment_variables(self, monkeypatch: pytest.MonkeyPatch) -> None:
+        # Test that the proxy environment variables are set correctly
+        monkeypatch.setenv("HTTPS_PROXY", "https://example.org")
+
+        client = DefaultHttpxClient()
+
+        mounts = tuple(client._mounts.items())
+        assert len(mounts) == 1
+        assert mounts[0][0].pattern == "https://"
+
+    @pytest.mark.filterwarnings("ignore:.*deprecated.*:DeprecationWarning")
+    def test_default_client_creation(self) -> None:
+        # Ensure that the client can be initialized without any exceptions
+        DefaultHttpxClient(
+            verify=True,
+            cert=None,
+            trust_env=True,
+            http1=True,
+            http2=False,
+            limits=httpx.Limits(max_connections=100, max_keepalive_connections=20),
+        )
+
     @pytest.mark.respx(base_url=base_url)
     def test_follow_redirects(self, respx_mock: MockRouter) -> None:
         # Test that the default follow_redirects=True allows following redirects
@@ -1799,6 +1823,28 @@ async def test_main() -> None:
 
                 time.sleep(0.1)
 
+    async def test_proxy_environment_variables(self, monkeypatch: pytest.MonkeyPatch) -> None:
+        # Test that the proxy environment variables are set correctly
+        monkeypatch.setenv("HTTPS_PROXY", "https://example.org")
+
+        client = DefaultAsyncHttpxClient()
+
+        mounts = tuple(client._mounts.items())
+        assert len(mounts) == 1
+        assert mounts[0][0].pattern == "https://"
+
+    @pytest.mark.filterwarnings("ignore:.*deprecated.*:DeprecationWarning")
+    async def test_default_client_creation(self) -> None:
+        # Ensure that the client can be initialized without any exceptions
+        DefaultAsyncHttpxClient(
+            verify=True,
+            cert=None,
+            trust_env=True,
+            http1=True,
+            http2=False,
+            limits=httpx.Limits(max_connections=100, max_keepalive_connections=20),
+        )
+
     @pytest.mark.respx(base_url=base_url)
     async def test_follow_redirects(self, respx_mock: MockRouter) -> None:
         # Test that the default follow_redirects=True allows following redirects