diff --git a/httpcore/_async/connection.py b/httpcore/_async/connection.py
index 2add4d857..335366a83 100644
--- a/httpcore/_async/connection.py
+++ b/httpcore/_async/connection.py
@@ -3,6 +3,7 @@
 
 from .._backends.auto import AsyncBackend, AsyncLock, AsyncSocketStream, AutoBackend
 from .._exceptions import ConnectError, ConnectTimeout
+from .._ssl import default_ssl_context
 from .._types import URL, Headers, Origin, TimeoutDict
 from .._utils import exponential_backoff, get_logger, url_to_origin
 from .base import AsyncByteStream, AsyncHTTPTransport, NewConnectionRequired
@@ -33,7 +34,9 @@ def __init__(
         self._http2_enabled = http2
         self._keepalive_expiry = keepalive_expiry
         self._uds = uds
-        self._ssl_context = SSLContext() if ssl_context is None else ssl_context
+        self._ssl_context = (
+            default_ssl_context() if ssl_context is None else ssl_context
+        )
         self.socket = socket
         self._local_address = local_address
         self._retries = retries
diff --git a/httpcore/_async/connection_pool.py b/httpcore/_async/connection_pool.py
index f86c2277c..a5f9c336a 100644
--- a/httpcore/_async/connection_pool.py
+++ b/httpcore/_async/connection_pool.py
@@ -15,6 +15,7 @@
 from .._backends.auto import AsyncBackend, AsyncLock, AsyncSemaphore
 from .._backends.base import lookup_async_backend
 from .._exceptions import LocalProtocolError, PoolTimeout, UnsupportedProtocol
+from .._ssl import default_ssl_context
 from .._threadlock import ThreadLock
 from .._types import URL, Headers, Origin, TimeoutDict
 from .._utils import get_logger, origin_to_url_string, url_to_origin
@@ -125,7 +126,9 @@ def __init__(
         if isinstance(backend, str):
             backend = lookup_async_backend(backend)
 
-        self._ssl_context = SSLContext() if ssl_context is None else ssl_context
+        self._ssl_context = (
+            default_ssl_context() if ssl_context is None else ssl_context
+        )
         self._max_connections = max_connections
         self._max_keepalive_connections = max_keepalive_connections
         self._keepalive_expiry = keepalive_expiry
diff --git a/httpcore/_async/http2.py b/httpcore/_async/http2.py
index 35a4e0911..6fe778d75 100644
--- a/httpcore/_async/http2.py
+++ b/httpcore/_async/http2.py
@@ -51,7 +51,7 @@ def __init__(
         self._exhausted_available_stream_ids = False
 
     def __repr__(self) -> str:
-        return f"<AsyncHTTP2Connection [{self._state}]>"
+        return f"<AsyncHTTP2Connection [{self._state.name}]>"
 
     def info(self) -> str:
         return f"HTTP/2, {self._state.name}, {len(self._streams)} streams"
diff --git a/httpcore/_backends/sync.py b/httpcore/_backends/sync.py
index ee8f94b7e..2be28d658 100644
--- a/httpcore/_backends/sync.py
+++ b/httpcore/_backends/sync.py
@@ -156,12 +156,16 @@ def open_uds_stream(
         with map_exceptions(exc_map):
             sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
             sock.settimeout(connect_timeout)
-            sock.connect(path)
-
-            if ssl_context is not None:
-                sock = ssl_context.wrap_socket(
-                    sock, server_hostname=hostname.decode("ascii")
-                )
+            try:
+                sock.connect(path)
+
+                if ssl_context is not None:
+                    sock = ssl_context.wrap_socket(
+                        sock, server_hostname=hostname.decode("ascii")
+                    )
+            except BaseException:
+                sock.close()
+                raise
 
             return SyncSocketStream(sock=sock)
 
diff --git a/httpcore/_ssl.py b/httpcore/_ssl.py
new file mode 100644
index 000000000..c99c5a679
--- /dev/null
+++ b/httpcore/_ssl.py
@@ -0,0 +1,9 @@
+import ssl
+
+import certifi
+
+
+def default_ssl_context() -> ssl.SSLContext:
+    context = ssl.create_default_context()
+    context.load_verify_locations(certifi.where())
+    return context
diff --git a/httpcore/_sync/connection.py b/httpcore/_sync/connection.py
index 382a4f9f6..21653e8f5 100644
--- a/httpcore/_sync/connection.py
+++ b/httpcore/_sync/connection.py
@@ -3,6 +3,7 @@
 
 from .._backends.sync import SyncBackend, SyncLock, SyncSocketStream, SyncBackend
 from .._exceptions import ConnectError, ConnectTimeout
+from .._ssl import default_ssl_context
 from .._types import URL, Headers, Origin, TimeoutDict
 from .._utils import exponential_backoff, get_logger, url_to_origin
 from .base import SyncByteStream, SyncHTTPTransport, NewConnectionRequired
@@ -33,7 +34,9 @@ def __init__(
         self._http2_enabled = http2
         self._keepalive_expiry = keepalive_expiry
         self._uds = uds
-        self._ssl_context = SSLContext() if ssl_context is None else ssl_context
+        self._ssl_context = (
+            default_ssl_context() if ssl_context is None else ssl_context
+        )
         self.socket = socket
         self._local_address = local_address
         self._retries = retries
diff --git a/httpcore/_sync/connection_pool.py b/httpcore/_sync/connection_pool.py
index 22ca98fa4..356aad8b9 100644
--- a/httpcore/_sync/connection_pool.py
+++ b/httpcore/_sync/connection_pool.py
@@ -15,6 +15,7 @@
 from .._backends.sync import SyncBackend, SyncLock, SyncSemaphore
 from .._backends.base import lookup_sync_backend
 from .._exceptions import LocalProtocolError, PoolTimeout, UnsupportedProtocol
+from .._ssl import default_ssl_context
 from .._threadlock import ThreadLock
 from .._types import URL, Headers, Origin, TimeoutDict
 from .._utils import get_logger, origin_to_url_string, url_to_origin
@@ -125,7 +126,9 @@ def __init__(
         if isinstance(backend, str):
             backend = lookup_sync_backend(backend)
 
-        self._ssl_context = SSLContext() if ssl_context is None else ssl_context
+        self._ssl_context = (
+            default_ssl_context() if ssl_context is None else ssl_context
+        )
         self._max_connections = max_connections
         self._max_keepalive_connections = max_keepalive_connections
         self._keepalive_expiry = keepalive_expiry
diff --git a/httpcore/_sync/http2.py b/httpcore/_sync/http2.py
index 90caf5faf..a6bd6ad13 100644
--- a/httpcore/_sync/http2.py
+++ b/httpcore/_sync/http2.py
@@ -51,7 +51,7 @@ def __init__(
         self._exhausted_available_stream_ids = False
 
     def __repr__(self) -> str:
-        return f"<SyncHTTP2Connection [{self._state}]>"
+        return f"<SyncHTTP2Connection [{self._state.name}]>"
 
     def info(self) -> str:
         return f"HTTP/2, {self._state.name}, {len(self._streams)} streams"
diff --git a/requirements.txt b/requirements.txt
index c8246d1a8..00333510f 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -38,3 +38,4 @@ pytest-trio==0.7.0
 pytest-asyncio==0.15.1
 trustme==0.8.0
 uvicorn==0.12.1; python_version < '3.7'
+types-certifi==0.1.4
diff --git a/setup.cfg b/setup.cfg
index 0e23b0624..fd215b5f6 100644
--- a/setup.cfg
+++ b/setup.cfg
@@ -21,6 +21,9 @@ skip = httpcore/_sync/,tests/sync_tests/
 
 [tool:pytest]
 addopts = -rxXs
+filterwarnings =
+  error
+  default:::hypercorn
 markers =
   copied_from(source, changes=None): mark test as copied from somewhere else, along with a description of changes made to accodomate e.g. our test setup
 
diff --git a/setup.py b/setup.py
index 3f5648d16..689ae12a9 100644
--- a/setup.py
+++ b/setup.py
@@ -53,7 +53,7 @@ def get_packages(package):
     packages=get_packages("httpcore"),
     include_package_data=True,
     zip_safe=False,
-    install_requires=["h11>=0.11,<0.13", "sniffio==1.*", "anyio==3.*"],
+    install_requires=["h11>=0.11,<0.13", "sniffio==1.*", "anyio==3.*", "certifi"],
     extras_require={
         "http2": ["h2>=3,<5"],
     },
diff --git a/tests/async_tests/test_interfaces.py b/tests/async_tests/test_interfaces.py
index ce547f820..3fc093eab 100644
--- a/tests/async_tests/test_interfaces.py
+++ b/tests/async_tests/test_interfaces.py
@@ -1,4 +1,5 @@
 import platform
+import ssl
 from typing import Tuple
 
 import pytest
@@ -52,8 +53,12 @@ async def test_http_request(backend: str, server: Server) -> None:
 
 
 @pytest.mark.anyio
-async def test_https_request(backend: str, https_server: Server) -> None:
-    async with httpcore.AsyncConnectionPool(backend=backend) as http:
+async def test_https_request(
+    backend: str, https_server: Server, ssl_context: ssl.SSLContext
+) -> None:
+    async with httpcore.AsyncConnectionPool(
+        backend=backend, ssl_context=ssl_context
+    ) as http:
         status_code, headers, stream, extensions = await http.handle_async_request(
             method=b"GET",
             url=(b"https", *https_server.netloc, b"/"),
@@ -92,8 +97,12 @@ async def test_request_unsupported_protocol(
 
 
 @pytest.mark.anyio
-async def test_http2_request(backend: str, https_server: Server) -> None:
-    async with httpcore.AsyncConnectionPool(backend=backend, http2=True) as http:
+async def test_http2_request(
+    backend: str, https_server: Server, ssl_context: ssl.SSLContext
+) -> None:
+    async with httpcore.AsyncConnectionPool(
+        backend=backend, http2=True, ssl_context=ssl_context
+    ) as http:
         status_code, headers, stream, extensions = await http.handle_async_request(
             method=b"GET",
             url=(b"https", *https_server.netloc, b"/"),
@@ -173,9 +182,11 @@ async def test_http_request_reuse_connection(backend: str, server: Server) -> No
 
 @pytest.mark.anyio
 async def test_https_request_reuse_connection(
-    backend: str, https_server: Server
+    backend: str, https_server: Server, ssl_context: ssl.SSLContext
 ) -> None:
-    async with httpcore.AsyncConnectionPool(backend=backend) as http:
+    async with httpcore.AsyncConnectionPool(
+        backend=backend, ssl_context=ssl_context
+    ) as http:
         status_code, headers, stream, extensions = await http.handle_async_request(
             method=b"GET",
             url=(b"https", *https_server.netloc, b"/"),
@@ -291,11 +302,6 @@ async def test_http_proxy(
 @pytest.mark.parametrize("proxy_mode", ["DEFAULT", "FORWARD_ONLY", "TUNNEL_ONLY"])
 @pytest.mark.parametrize("protocol,port", [(b"http", 80), (b"https", 443)])
 @pytest.mark.trio
-# Filter out ssl module deprecation warnings and asyncio module resource warning,
-# convert other warnings to errors.
-@pytest.mark.filterwarnings("ignore:.*(SSLContext|PROTOCOL_TLS):DeprecationWarning")
-@pytest.mark.filterwarnings("ignore::ResourceWarning:asyncio")
-@pytest.mark.filterwarnings("error")
 async def test_proxy_socket_does_not_leak_when_the_connection_hasnt_been_added_to_pool(
     proxy_server: URL,
     server: Server,
@@ -353,6 +359,7 @@ async def test_proxy_https_requests(
     proxy_mode: str,
     http2: bool,
     https_server: Server,
+    ssl_context: ssl.SSLContext,
 ) -> None:
     max_connections = 1
     async with httpcore.AsyncHTTPProxy(
@@ -360,6 +367,7 @@ async def test_proxy_https_requests(
         proxy_mode=proxy_mode,
         max_connections=max_connections,
         http2=http2,
+        ssl_context=ssl_context,
     ) as http:
         status_code, headers, stream, extensions = await http.handle_async_request(
             method=b"GET",
@@ -412,9 +420,13 @@ async def test_connection_pool_get_connection_info(
     expected_during_idle: dict,
     backend: str,
     https_server: Server,
+    ssl_context: ssl.SSLContext,
 ) -> None:
     async with httpcore.AsyncConnectionPool(
-        http2=http2, keepalive_expiry=keepalive_expiry, backend=backend
+        http2=http2,
+        keepalive_expiry=keepalive_expiry,
+        backend=backend,
+        ssl_context=ssl_context,
     ) as http:
         _, _, stream_1, _ = await http.handle_async_request(
             method=b"GET",
diff --git a/tests/conftest.py b/tests/conftest.py
index 0ba96fdc9..994f31c4f 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -1,5 +1,6 @@
 import contextlib
 import os
+import ssl
 import threading
 import time
 import typing
@@ -7,6 +8,7 @@
 import pytest
 import trustme
 
+from httpcore._ssl import default_ssl_context
 from httpcore._types import URL
 
 from .utils import HypercornServer, LiveServer, Server, http_proxy_server
@@ -140,6 +142,19 @@ def localhost_cert_private_key_file(
         yield tmp
 
 
+@pytest.fixture(scope="session")
+def ssl_context(
+    cert_authority: trustme.CA, localhost_cert: trustme.LeafCert
+) -> ssl.SSLContext:
+    ssl_context = default_ssl_context()
+
+    if hypercorn is not None:
+        cert_authority.configure_trust(ssl_context)
+        localhost_cert.configure_cert(ssl_context)
+
+    return ssl_context
+
+
 @pytest.fixture(scope="session")
 def https_server(
     localhost_cert_pem_file: str, localhost_cert_private_key_file: str
diff --git a/tests/sync_tests/test_interfaces.py b/tests/sync_tests/test_interfaces.py
index cc31ab345..d80ceba73 100644
--- a/tests/sync_tests/test_interfaces.py
+++ b/tests/sync_tests/test_interfaces.py
@@ -1,4 +1,5 @@
 import platform
+import ssl
 from typing import Tuple
 
 import pytest
@@ -52,8 +53,12 @@ def test_http_request(backend: str, server: Server) -> None:
 
 
 
-def test_https_request(backend: str, https_server: Server) -> None:
-    with httpcore.SyncConnectionPool(backend=backend) as http:
+def test_https_request(
+    backend: str, https_server: Server, ssl_context: ssl.SSLContext
+) -> None:
+    with httpcore.SyncConnectionPool(
+        backend=backend, ssl_context=ssl_context
+    ) as http:
         status_code, headers, stream, extensions = http.handle_request(
             method=b"GET",
             url=(b"https", *https_server.netloc, b"/"),
@@ -92,8 +97,12 @@ def test_request_unsupported_protocol(
 
 
 
-def test_http2_request(backend: str, https_server: Server) -> None:
-    with httpcore.SyncConnectionPool(backend=backend, http2=True) as http:
+def test_http2_request(
+    backend: str, https_server: Server, ssl_context: ssl.SSLContext
+) -> None:
+    with httpcore.SyncConnectionPool(
+        backend=backend, http2=True, ssl_context=ssl_context
+    ) as http:
         status_code, headers, stream, extensions = http.handle_request(
             method=b"GET",
             url=(b"https", *https_server.netloc, b"/"),
@@ -173,9 +182,11 @@ def test_http_request_reuse_connection(backend: str, server: Server) -> None:
 
 
 def test_https_request_reuse_connection(
-    backend: str, https_server: Server
+    backend: str, https_server: Server, ssl_context: ssl.SSLContext
 ) -> None:
-    with httpcore.SyncConnectionPool(backend=backend) as http:
+    with httpcore.SyncConnectionPool(
+        backend=backend, ssl_context=ssl_context
+    ) as http:
         status_code, headers, stream, extensions = http.handle_request(
             method=b"GET",
             url=(b"https", *https_server.netloc, b"/"),
@@ -291,11 +302,6 @@ def test_http_proxy(
 @pytest.mark.parametrize("proxy_mode", ["DEFAULT", "FORWARD_ONLY", "TUNNEL_ONLY"])
 @pytest.mark.parametrize("protocol,port", [(b"http", 80), (b"https", 443)])
 
-# Filter out ssl module deprecation warnings and asyncio module resource warning,
-# convert other warnings to errors.
-@pytest.mark.filterwarnings("ignore:.*(SSLContext|PROTOCOL_TLS):DeprecationWarning")
-@pytest.mark.filterwarnings("ignore::ResourceWarning:asyncio")
-@pytest.mark.filterwarnings("error")
 def test_proxy_socket_does_not_leak_when_the_connection_hasnt_been_added_to_pool(
     proxy_server: URL,
     server: Server,
@@ -353,6 +359,7 @@ def test_proxy_https_requests(
     proxy_mode: str,
     http2: bool,
     https_server: Server,
+    ssl_context: ssl.SSLContext,
 ) -> None:
     max_connections = 1
     with httpcore.SyncHTTPProxy(
@@ -360,6 +367,7 @@ def test_proxy_https_requests(
         proxy_mode=proxy_mode,
         max_connections=max_connections,
         http2=http2,
+        ssl_context=ssl_context,
     ) as http:
         status_code, headers, stream, extensions = http.handle_request(
             method=b"GET",
@@ -412,9 +420,13 @@ def test_connection_pool_get_connection_info(
     expected_during_idle: dict,
     backend: str,
     https_server: Server,
+    ssl_context: ssl.SSLContext,
 ) -> None:
     with httpcore.SyncConnectionPool(
-        http2=http2, keepalive_expiry=keepalive_expiry, backend=backend
+        http2=http2,
+        keepalive_expiry=keepalive_expiry,
+        backend=backend,
+        ssl_context=ssl_context,
     ) as http:
         _, _, stream_1, _ = http.handle_request(
             method=b"GET",
diff --git a/tests/utils.py b/tests/utils.py
index de3091255..f14836484 100644
--- a/tests/utils.py
+++ b/tests/utils.py
@@ -179,6 +179,7 @@ def http_proxy_server(proxy_host: str, proxy_port: int):
         finally:
             if proc is not None:
                 proc.kill()
+                proc.communicate()
 
 
 @contextlib.contextmanager