diff --git a/src/main/java/io/vertx/httpproxy/impl/ReverseProxy.java b/src/main/java/io/vertx/httpproxy/impl/ReverseProxy.java
index 77848b6..cda186f 100644
--- a/src/main/java/io/vertx/httpproxy/impl/ReverseProxy.java
+++ b/src/main/java/io/vertx/httpproxy/impl/ReverseProxy.java
@@ -28,6 +28,7 @@
 import java.util.*;
 
 import static io.vertx.core.http.HttpHeaders.CONNECTION;
+import static io.vertx.core.http.HttpHeaders.HOST;
 import static io.vertx.core.http.HttpHeaders.UPGRADE;
 
 public class ReverseProxy implements HttpProxy {
@@ -175,11 +176,18 @@ public Future<ProxyResponse> sendRequest() {
           return resolveOrigin(this).compose(request -> {
             request.setMethod(request().getMethod());
             request.setURI(request().getURI());
-            // Firefox is known to send an unexpected connection header value
-            // Connection=keep-alive, Upgrade
-            // It leads to a failure in websocket proxying
-            // So we make sure the standard value is sent to the backend
-            request.headers().addAll(request().headers()).set(CONNECTION, UPGRADE);
+            for (Map.Entry<String, String> header : request().headers()) {
+              String name = header.getKey();
+              if (name.equalsIgnoreCase(CONNECTION.toString())) {
+                // Firefox is known to send an unexpected connection header value
+                // Connection=keep-alive, Upgrade
+                // It leads to a failure in websocket proxying
+                // So we make sure the standard value is sent to the backend
+                request.headers().set(CONNECTION, UPGRADE);
+              } else if (!name.equalsIgnoreCase(HOST.toString())) {
+                request.headers().add(name, header.getValue());
+              }
+            }
             Future<HttpClientResponse> responseFuture = request.connect();
             ReadStream<Buffer> readStream = request().getBody().stream();
             readStream.handler(request::write);
diff --git a/src/test/java/io/vertx/tests/WebSocketTest.java b/src/test/java/io/vertx/tests/WebSocketTest.java
index 6471468..1f2b139 100644
--- a/src/test/java/io/vertx/tests/WebSocketTest.java
+++ b/src/test/java/io/vertx/tests/WebSocketTest.java
@@ -155,6 +155,37 @@ public void testWebSocketFirefox(TestContext ctx) {
     }));
   }
 
+  @Test
+  public void testWebSocketHostHeader(TestContext ctx) {
+    Async async = ctx.async();
+    SocketAddress backend = startHttpBackend(ctx, 8081, req -> {
+      ctx.assertEquals("localhost:8081", req.headers().get("Host"));
+      Future<ServerWebSocket> fut = req.toWebSocket();
+      fut.onComplete(ctx.asyncAssertSuccess(ws -> {
+        ws.closeHandler(v -> {
+          async.complete();
+        });
+      }));
+    });
+    startProxy(backend);
+    httpClient = vertx.createHttpClient();
+    RequestOptions options = new RequestOptions()
+      .setPort(8080)
+      .setHost("localhost")
+      .setURI("/ws")
+      .putHeader("Origin", "http://localhost:8080")
+      .putHeader("Connection", "Upgrade")
+      .putHeader("Upgrade", "Websocket")
+      .putHeader("Sec-WebSocket-Version", "13")
+      .putHeader("Sec-WebSocket-Key", "xy6UoM3l3TcREmAeAhZuYQ==");
+    httpClient.request(options).onComplete(ctx.asyncAssertSuccess(clientRequest -> {
+      clientRequest.connect().onComplete(ctx.asyncAssertSuccess(response -> {
+        ctx.assertEquals(101, response.statusCode());
+        response.netSocket().close();
+      }));
+    }));
+  }
+
   @Test
   public void testVariableFromInterceptor(TestContext ctx) {
     Async async = ctx.async();