diff --git a/src/server/conn/auto/mod.rs b/src/server/conn/auto/mod.rs
index 7b887ce2..9290aeb3 100644
--- a/src/server/conn/auto/mod.rs
+++ b/src/server/conn/auto/mod.rs
@@ -114,10 +114,6 @@ impl<E> Builder<E> {
     }
 
     /// Only accepts HTTP/2
-    ///
-    /// Does not do anything if used with [`serve_connection_with_upgrades`]
-    ///
-    /// [`serve_connection_with_upgrades`]: Builder::serve_connection_with_upgrades
     #[cfg(feature = "http2")]
     pub fn http2_only(mut self) -> Self {
         assert!(self.version.is_none());
@@ -126,10 +122,6 @@ impl<E> Builder<E> {
     }
 
     /// Only accepts HTTP/1
-    ///
-    /// Does not do anything if used with [`serve_connection_with_upgrades`]
-    ///
-    /// [`serve_connection_with_upgrades`]: Builder::serve_connection_with_upgrades
     #[cfg(feature = "http1")]
     pub fn http1_only(mut self) -> Self {
         assert!(self.version.is_none());
@@ -268,13 +260,28 @@ impl<E> Builder<E> {
         I: Read + Write + Unpin + Send + 'static,
         E: HttpServerConnExec<S::Future, B>,
     {
-        UpgradeableConnection {
-            state: UpgradeableConnState::ReadVersion {
+        let state = match self.version {
+            #[cfg(feature = "http1")]
+            Some(Version::H1) => {
+                let io = Rewind::new_buffered(io, Bytes::new());
+                let conn = self.http1.serve_connection(io, service).with_upgrades();
+                UpgradeableConnState::H1 { conn }
+            }
+            #[cfg(feature = "http2")]
+            Some(Version::H2) => {
+                let io = Rewind::new_buffered(io, Bytes::new());
+                let conn = self.http2.serve_connection(io, service);
+                UpgradeableConnState::H2 { conn }
+            }
+            #[cfg(any(feature = "http1", feature = "http2"))]
+            _ => UpgradeableConnState::ReadVersion {
                 read_version: read_version(io),
                 builder: Cow::Borrowed(self),
                 service: Some(service),
             },
-        }
+        };
+
+        UpgradeableConnection { state }
     }
 }
 
@@ -1188,7 +1195,7 @@ mod tests {
     #[cfg(not(miri))]
     #[tokio::test]
     async fn http1() {
-        let addr = start_server(false, false).await;
+        let addr = start_server(HttpVersion::Any).await;
         let mut sender = connect_h1(addr).await;
 
         let response = sender
@@ -1204,7 +1211,7 @@ mod tests {
     #[cfg(not(miri))]
     #[tokio::test]
     async fn http2() {
-        let addr = start_server(false, false).await;
+        let addr = start_server(HttpVersion::Any).await;
         let mut sender = connect_h2(addr).await;
 
         let response = sender
@@ -1220,7 +1227,7 @@ mod tests {
     #[cfg(not(miri))]
     #[tokio::test]
     async fn http2_only() {
-        let addr = start_server(false, true).await;
+        let addr = start_server(HttpVersion::H2Only).await;
         let mut sender = connect_h2(addr).await;
 
         let response = sender
@@ -1236,7 +1243,7 @@ mod tests {
     #[cfg(not(miri))]
     #[tokio::test]
     async fn http2_only_fail_if_client_is_http1() {
-        let addr = start_server(false, true).await;
+        let addr = start_server(HttpVersion::H2Only).await;
         let mut sender = connect_h1(addr).await;
 
         let _ = sender
@@ -1248,7 +1255,7 @@ mod tests {
     #[cfg(not(miri))]
     #[tokio::test]
     async fn http1_only() {
-        let addr = start_server(true, false).await;
+        let addr = start_server(HttpVersion::H1Only).await;
         let mut sender = connect_h1(addr).await;
 
         let response = sender
@@ -1264,7 +1271,7 @@ mod tests {
     #[cfg(not(miri))]
     #[tokio::test]
     async fn http1_only_fail_if_client_is_http2() {
-        let addr = start_server(true, false).await;
+        let addr = start_server(HttpVersion::H1Only).await;
         let mut sender = connect_h2(addr).await;
 
         let _ = sender
@@ -1338,7 +1345,14 @@ mod tests {
         sender
     }
 
-    async fn start_server(h1_only: bool, h2_only: bool) -> SocketAddr {
+    #[derive(Clone, Copy)]
+    enum HttpVersion {
+        H1Only,
+        H2Only,
+        Any,
+    }
+
+    async fn start_server(version: HttpVersion) -> SocketAddr {
         let addr: SocketAddr = ([127, 0, 0, 1], 0).into();
         let listener = TcpListener::bind(addr).await.unwrap();
 
@@ -1350,20 +1364,22 @@ mod tests {
                 let stream = TokioIo::new(stream);
                 tokio::task::spawn(async move {
                     let mut builder = auto::Builder::new(TokioExecutor::new());
-                    if h1_only {
-                        builder = builder.http1_only();
-                        builder.serve_connection(stream, service_fn(hello)).await
-                    } else if h2_only {
-                        builder = builder.http2_only();
-                        builder.serve_connection(stream, service_fn(hello)).await
-                    } else {
-                        builder
-                            .http2()
-                            .max_header_list_size(4096)
-                            .serve_connection_with_upgrades(stream, service_fn(hello))
-                            .await
-                    }
-                    .unwrap();
+                    match version {
+                        HttpVersion::H1Only => {
+                            builder = builder.http1_only();
+                        }
+                        HttpVersion::H2Only => {
+                            builder = builder.http2_only();
+                        }
+                        HttpVersion::Any => (),
+                    };
+
+                    builder
+                        .http2()
+                        .max_header_list_size(4096)
+                        .serve_connection_with_upgrades(stream, service_fn(hello))
+                        .await
+                        .unwrap();
                 });
             }
         });