diff --git a/pyproject.toml b/pyproject.toml
index a313730..61aea4f 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -25,6 +25,6 @@ classifiers = [
     "Topic :: Internet :: WWW/HTTP",
 ]
 dependencies = [
-    "truststore==0.10",
     "h11==0.14",
+    "truststore==0.10",
 ]
diff --git a/src/ahttpx/_client.py b/src/ahttpx/_client.py
index 95d6df9..61a3977 100644
--- a/src/ahttpx/_client.py
+++ b/src/ahttpx/_client.py
@@ -11,9 +11,18 @@
 
 
 class Client:
-    def __init__(self):
-        self.url = URL("")
-        self.headers = Headers({"User-Agent": "dev"})
+    def __init__(
+        self,
+        url: URL | str | None = None,
+        headers: Headers | Mapping[str, str] | None = None
+    ):
+        if url is None:
+            url = ""
+        if headers is None:
+            headers = {"User-Agent": "dev"}
+
+        self.url = URL(url)
+        self.headers = Headers(headers)
         self.transport = ConnectionPool()
         self.via = RedirectMiddleware(self.transport)
 
diff --git a/src/ahttpx/_pool.py b/src/ahttpx/_pool.py
index c27a443..de00ac8 100644
--- a/src/ahttpx/_pool.py
+++ b/src/ahttpx/_pool.py
@@ -5,6 +5,7 @@
 import types
 
 import h11
+import truststore
 
 from ._models import Request, Response, URL
 from ._network import Lock, NetworkBackend, Semaphore, NetworkStream
@@ -12,8 +13,6 @@
 
 class ConnectionPool:
     def __init__(self):
-        import truststore
-
         self._connections = []
         self._ctx = truststore.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
         self._network_backend = NetworkBackend()
diff --git a/src/httpx/_client.py b/src/httpx/_client.py
index b04083e..ee61eaf 100644
--- a/src/httpx/_client.py
+++ b/src/httpx/_client.py
@@ -11,10 +11,20 @@
 
 
 class Client:
-    def __init__(self):
-        self.url = URL("")
-        self.headers = Headers({"User-Agent": "dev"})
-        self.transport = RedirectMiddleware(ConnectionPool())
+    def __init__(
+        self,
+        url: URL | str | None = None,
+        headers: Headers | Mapping[str, str] | None = None
+    ):
+        if url is None:
+            url = ""
+        if headers is None:
+            headers = {"User-Agent": "dev"}
+
+        self.url = URL(url)
+        self.headers = Headers(headers)
+        self.transport = ConnectionPool()
+        self.via = RedirectMiddleware(self.transport)
 
     def build_request(
         self,
@@ -38,7 +48,7 @@ def request(
         content: Content | Iterable[bytes] | bytes | None = None,
     ) -> Response:
         request = self.build_request(method, url, headers=headers, content=content)
-        with self.transport.send(request) as response:
+        with self.via.send(request) as response:
             response.read()
         return response
 
@@ -51,7 +61,7 @@ def stream(
         content: Content | Iterable[bytes] | bytes | None = None,
     ) -> Iterator[Response]:
         request = self.build_request(method, url, headers=headers, content=content)
-        with self.transport.send(request) as response:
+        with self.via.send(request) as response:
             yield response
 
     def get(
diff --git a/src/httpx/_pool.py b/src/httpx/_pool.py
index 9973f73..9ba55cc 100644
--- a/src/httpx/_pool.py
+++ b/src/httpx/_pool.py
@@ -5,6 +5,7 @@
 import types
 
 import h11
+import truststore
 
 from ._models import Request, Response, URL
 from ._network import Lock, NetworkBackend, Semaphore, NetworkStream
@@ -12,8 +13,6 @@
 
 class ConnectionPool:
     def __init__(self):
-        import truststore
-
         self._connections = []
         self._ctx = truststore.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
         self._network_backend = NetworkBackend()