diff --git a/docs/project/changelog.rst b/docs/project/changelog.rst
index 7e2968826..12fc8c32e 100644
--- a/docs/project/changelog.rst
+++ b/docs/project/changelog.rst
@@ -32,6 +32,11 @@ notice.
 
 *In development*
 
+Improvements
+............
+
+* Added support for HTTP/1.0 proxies.
+
 15.0.1
 ------
 
diff --git a/src/websockets/asyncio/client.py b/src/websockets/asyncio/client.py
index 38a56ddda..aa0d6f774 100644
--- a/src/websockets/asyncio/client.py
+++ b/src/websockets/asyncio/client.py
@@ -754,7 +754,7 @@ def __init__(
             self.reader.read_line,
             self.reader.read_exact,
             self.reader.read_to_eof,
-            include_body=False,
+            proxy=True,
         )
 
         loop = asyncio.get_running_loop()
diff --git a/src/websockets/http11.py b/src/websockets/http11.py
index 177c927fb..290ef087e 100644
--- a/src/websockets/http11.py
+++ b/src/websockets/http11.py
@@ -213,7 +213,7 @@ def parse(
         read_line: Callable[[int], Generator[None, None, bytes]],
         read_exact: Callable[[int], Generator[None, None, bytes]],
         read_to_eof: Callable[[int], Generator[None, None, bytes]],
-        include_body: bool = True,
+        proxy: bool = False,
     ) -> Generator[None, None, Response]:
         """
         Parse a WebSocket handshake response.
@@ -249,10 +249,17 @@ def parse(
             protocol, raw_status_code, raw_reason = status_line.split(b" ", 2)
         except ValueError:  # not enough values to unpack (expected 3, got 1-2)
             raise ValueError(f"invalid HTTP status line: {d(status_line)}") from None
-        if protocol != b"HTTP/1.1":
-            raise ValueError(
-                f"unsupported protocol; expected HTTP/1.1: {d(status_line)}"
-            )
+        if proxy:  # some proxies still use HTTP/1.0
+            if protocol not in [b"HTTP/1.1", b"HTTP/1.0"]:
+                raise ValueError(
+                    f"unsupported protocol; expected HTTP/1.1 or HTTP/1.0: "
+                    f"{d(status_line)}"
+                )
+        else:
+            if protocol != b"HTTP/1.1":
+                raise ValueError(
+                    f"unsupported protocol; expected HTTP/1.1: {d(status_line)}"
+                )
         try:
             status_code = int(raw_status_code)
         except ValueError:  # invalid literal for int() with base 10
@@ -269,12 +276,12 @@ def parse(
 
         headers = yield from parse_headers(read_line)
 
-        if include_body:
+        if proxy:
+            body = b""
+        else:
             body = yield from read_body(
                 status_code, headers, read_line, read_exact, read_to_eof
             )
-        else:
-            body = b""
 
         return cls(status_code, reason, headers, body)
 
diff --git a/src/websockets/sync/client.py b/src/websockets/sync/client.py
index 58cb84710..b161523f8 100644
--- a/src/websockets/sync/client.py
+++ b/src/websockets/sync/client.py
@@ -498,7 +498,7 @@ def read_connect_response(sock: socket.socket, deadline: Deadline) -> Response:
         reader.read_line,
         reader.read_exact,
         reader.read_to_eof,
-        include_body=False,
+        proxy=True,
     )
     try:
         while True:
diff --git a/tests/test_http11.py b/tests/test_http11.py
index ca7a1bc86..3328b3b5e 100644
--- a/tests/test_http11.py
+++ b/tests/test_http11.py
@@ -328,11 +328,28 @@ def test_parse_body_not_modified(self):
         response = self.assertGeneratorReturns(self.parse())
         self.assertEqual(response.body, b"")
 
-    def test_parse_without_body(self):
+    def test_parse_proxy_response_does_not_read_body(self):
         self.reader.feed_data(b"HTTP/1.1 200 Connection Established\r\n\r\n")
-        response = self.assertGeneratorReturns(self.parse(include_body=False))
+        response = self.assertGeneratorReturns(self.parse(proxy=True))
         self.assertEqual(response.body, b"")
 
+    def test_parse_proxy_http10(self):
+        self.reader.feed_data(b"HTTP/1.0 200 OK\r\nContent-Length: 0\r\n\r\n")
+        response = self.assertGeneratorReturns(self.parse(proxy=True))
+        self.assertEqual(response.status_code, 200)
+        self.assertEqual(response.reason_phrase, "OK")
+        self.assertEqual(response.body, b"")
+
+    def test_parse_proxy_unsupported_protocol(self):
+        self.reader.feed_data(b"HTTP/1.2 400 Bad Request\r\n\r\n")
+        with self.assertRaises(ValueError) as raised:
+            next(self.parse(proxy=True))
+        self.assertEqual(
+            str(raised.exception),
+            "unsupported protocol; expected HTTP/1.1 or HTTP/1.0: "
+            "HTTP/1.2 400 Bad Request",
+        )
+
     def test_serialize(self):
         # Example from the protocol overview in RFC 6455
         response = Response(