diff --git a/httpcore/_async/connection.py b/httpcore/_async/connection.py
index b42581df..7894d0e0 100644
--- a/httpcore/_async/connection.py
+++ b/httpcore/_async/connection.py
@@ -143,7 +143,11 @@ async def _connect(self, request: Request) -> AsyncNetworkStream:
                         if self._ssl_context is None
                         else self._ssl_context
                     )
-                    alpn_protocols = ["http/1.1", "h2"] if self._http2 else ["http/1.1"]
+                    alpn_protocols = []
+                    if self._http2:
+                        alpn_protocols.append("h2")
+                    if self._http1:
+                        alpn_protocols.append("http/1.1")
                     ssl_context.set_alpn_protocols(alpn_protocols)
 
                     kwargs = {
diff --git a/httpcore/_async/http_proxy.py b/httpcore/_async/http_proxy.py
index cc9d9206..3b7c3c24 100644
--- a/httpcore/_async/http_proxy.py
+++ b/httpcore/_async/http_proxy.py
@@ -304,7 +304,11 @@ async def handle_async_request(self, request: Request) -> Response:
                     if self._ssl_context is None
                     else self._ssl_context
                 )
-                alpn_protocols = ["http/1.1", "h2"] if self._http2 else ["http/1.1"]
+                alpn_protocols = []
+                if self._http2:
+                    alpn_protocols.append("h2")
+                if self._http1:
+                    alpn_protocols.append("http/1.1")
                 ssl_context.set_alpn_protocols(alpn_protocols)
 
                 kwargs = {
diff --git a/httpcore/_async/socks_proxy.py b/httpcore/_async/socks_proxy.py
index b363f55a..1bd9c704 100644
--- a/httpcore/_async/socks_proxy.py
+++ b/httpcore/_async/socks_proxy.py
@@ -251,9 +251,11 @@ async def handle_async_request(self, request: Request) -> Response:
                             if self._ssl_context is None
                             else self._ssl_context
                         )
-                        alpn_protocols = (
-                            ["http/1.1", "h2"] if self._http2 else ["http/1.1"]
-                        )
+                        alpn_protocols = []
+                        if self._http2:
+                            alpn_protocols.append("h2")
+                        if self._http1:
+                            alpn_protocols.append("http/1.1")
                         ssl_context.set_alpn_protocols(alpn_protocols)
 
                         kwargs = {
diff --git a/httpcore/_sync/connection.py b/httpcore/_sync/connection.py
index 363f8be8..d5d70212 100644
--- a/httpcore/_sync/connection.py
+++ b/httpcore/_sync/connection.py
@@ -143,7 +143,11 @@ def _connect(self, request: Request) -> NetworkStream:
                         if self._ssl_context is None
                         else self._ssl_context
                     )
-                    alpn_protocols = ["http/1.1", "h2"] if self._http2 else ["http/1.1"]
+                    alpn_protocols = []
+                    if self._http2:
+                        alpn_protocols.append("h2")
+                    if self._http1:
+                        alpn_protocols.append("http/1.1")
                     ssl_context.set_alpn_protocols(alpn_protocols)
 
                     kwargs = {
diff --git a/httpcore/_sync/http_proxy.py b/httpcore/_sync/http_proxy.py
index ecca88f7..fec02a53 100644
--- a/httpcore/_sync/http_proxy.py
+++ b/httpcore/_sync/http_proxy.py
@@ -304,7 +304,11 @@ def handle_request(self, request: Request) -> Response:
                     if self._ssl_context is None
                     else self._ssl_context
                 )
-                alpn_protocols = ["http/1.1", "h2"] if self._http2 else ["http/1.1"]
+                alpn_protocols = []
+                if self._http2:
+                    alpn_protocols.append("h2")
+                if self._http1:
+                    alpn_protocols.append("http/1.1")
                 ssl_context.set_alpn_protocols(alpn_protocols)
 
                 kwargs = {
diff --git a/httpcore/_sync/socks_proxy.py b/httpcore/_sync/socks_proxy.py
index 0ca96ddf..4195f4c3 100644
--- a/httpcore/_sync/socks_proxy.py
+++ b/httpcore/_sync/socks_proxy.py
@@ -251,9 +251,11 @@ def handle_request(self, request: Request) -> Response:
                             if self._ssl_context is None
                             else self._ssl_context
                         )
-                        alpn_protocols = (
-                            ["http/1.1", "h2"] if self._http2 else ["http/1.1"]
-                        )
+                        alpn_protocols = []
+                        if self._http2:
+                            alpn_protocols.append("h2")
+                        if self._http1:
+                            alpn_protocols.append("http/1.1")
                         ssl_context.set_alpn_protocols(alpn_protocols)
 
                         kwargs = {
diff --git a/tests/_async/test_socks_proxy.py b/tests/_async/test_socks_proxy.py
index 907594a4..01e184e2 100644
--- a/tests/_async/test_socks_proxy.py
+++ b/tests/_async/test_socks_proxy.py
@@ -27,6 +27,8 @@ async def test_socks5_request():
     async with httpcore.AsyncConnectionPool(
         proxy=httpcore.Proxy("socks5://localhost:8080/"),
         network_backend=network_backend,
+        # We also enable h2, but will negotiated http1.1
+        http2=True,
     ) as proxy:
         # Sending an intial request, which once complete will return to the pool, IDLE.
         async with proxy.stream("GET", "https://example.com/") as response:
diff --git a/tests/_sync/test_socks_proxy.py b/tests/_sync/test_socks_proxy.py
index 89ec9fae..072cb3f9 100644
--- a/tests/_sync/test_socks_proxy.py
+++ b/tests/_sync/test_socks_proxy.py
@@ -27,6 +27,8 @@ def test_socks5_request():
     with httpcore.ConnectionPool(
         proxy=httpcore.Proxy("socks5://localhost:8080/"),
         network_backend=network_backend,
+        # We also enable h2, but will negotiated http1.1
+        http2=True,
     ) as proxy:
         # Sending an intial request, which once complete will return to the pool, IDLE.
         with proxy.stream("GET", "https://example.com/") as response: