@@ -1426,7 +1426,7 @@ func makeHttpHandler(logging bool, localMethod string, localRoute string, handle

 		}

 		if version.GreaterThan(api.APIVERSION) {

-			http.Error(w, fmt.Errorf("client and server don't have same version (client API version: %s, server API version: %s)", version, api.APIVERSION).Error(), http.StatusNotFound)

+			http.Error(w, fmt.Errorf("client and server don't have same version (client API version: %s, server API version: %s)", version, api.APIVERSION).Error(), http.StatusBadRequest)

 			return

 		}

@@ -46,6 +46,11 @@ You can still call an old version of the API using

 ### What's new

+**New!**

+When the daemon detects a version mismatch with the client, usually when

+the client is newer than the daemon, an HTTP 400 is now returned instead

+of a 404.

+

 `GET /containers/(id)/stats`

 **New!**

@@ -13,6 +13,8 @@ page_keywords: API, Docker, rcli, REST, documentation

  - The API tends to be REST, but for some complex commands, like `attach`

    or `pull`, the HTTP connection is hijacked to transport `STDOUT`,

    `STDIN` and `STDERR`.

+ - When the client API version is newer than the daemon's an HTTP

+   `400 Bad Request` error message is returned.

 # 2. Endpoints

@@ -2,6 +2,8 @@ package main

 import (

 	"net/http"

+	"net/http/httputil"

+	"time"

 	"github.com/go-check/check"

 )

@@ -23,3 +25,18 @@ func (s *DockerSuite) TestApiGetEnabledCors(c *check.C) {

 	//c.Assert(res.Header.Get("Access-Control-Allow-Origin"), check.Equals, "*")

 	//c.Assert(res.Header.Get("Access-Control-Allow-Headers"), check.Equals, "Origin, X-Requested-With, Content-Type, Accept, X-Registry-Auth")

 }

+

+func (s *DockerSuite) TestVersionStatusCode(c *check.C) {

+	conn, err := sockConn(time.Duration(10 * time.Second))

+	c.Assert(err, check.IsNil)

+

+	client := httputil.NewClientConn(conn, nil)

+	defer client.Close()

+

+	req, err := http.NewRequest("GET", "/v999.0/version", nil)

+	c.Assert(err, check.IsNil)

+	req.Header.Set("User-Agent", "Docker-Client/999.0")

+

+	res, err := client.Do(req)

+	c.Assert(res.StatusCode, check.Equals, http.StatusBadRequest)

+}