diff --git a/api/client/hijack.go b/api/client/hijack.go
index 5f4794a5e7..becb8a7479 100644
--- a/api/client/hijack.go
+++ b/api/client/hijack.go
@@ -149,7 +149,7 @@ func (cli *DockerCli) hijack(method, path string, setRawTerminal bool, in io.Rea
 		req.Header.Set(k, v)
 	}
 
-	req.Header.Set("User-Agent", "Docker-Client/"+dockerversion.VERSION)
+	req.Header.Set("User-Agent", "Docker-Client/"+dockerversion.VERSION+" ("+runtime.GOOS+")")
 	req.Header.Set("Content-Type", "text/plain")
 	req.Header.Set("Connection", "Upgrade")
 	req.Header.Set("Upgrade", "tcp")
diff --git a/api/client/utils.go b/api/client/utils.go
index 6fb9b256fd..3483d4727e 100644
--- a/api/client/utils.go
+++ b/api/client/utils.go
@@ -64,7 +64,7 @@ func (cli *DockerCli) clientRequest(method, path string, in io.Reader, headers m
 		req.Header.Set(k, v)
 	}
 
-	req.Header.Set("User-Agent", "Docker-Client/"+dockerversion.VERSION)
+	req.Header.Set("User-Agent", "Docker-Client/"+dockerversion.VERSION+" ("+runtime.GOOS+")")
 	req.URL.Host = cli.addr
 	req.URL.Scheme = cli.scheme
 
diff --git a/api/server/server.go b/api/server/server.go
index d7ec2d47d7..605fe2999b 100644
--- a/api/server/server.go
+++ b/api/server/server.go
@@ -1459,6 +1459,13 @@ func makeHttpHandler(logging bool, localMethod string, localRoute string, handle
 
 		if strings.Contains(r.Header.Get("User-Agent"), "Docker-Client/") {
 			userAgent := strings.Split(r.Header.Get("User-Agent"), "/")
+
+			// v1.20 onwards includes the GOOS of the client after the version
+			// such as Docker/1.7.0 (linux)
+			if len(userAgent) == 2 && strings.Contains(userAgent[1], " ") {
+				userAgent[1] = strings.Split(userAgent[1], " ")[0]
+			}
+
 			if len(userAgent) == 2 && !dockerVersion.Equal(version.Version(userAgent[1])) {
 				logrus.Debugf("Warning: client and server don't have the same version (client: %s, server: %s)", userAgent[1], dockerVersion)
 			}
diff --git a/integration-cli/docker_api_test.go b/integration-cli/docker_api_test.go
index 0bd48880a8..f1d0c327d6 100644
--- a/integration-cli/docker_api_test.go
+++ b/integration-cli/docker_api_test.go
@@ -35,7 +35,7 @@ func (s *DockerSuite) TestVersionStatusCode(c *check.C) {
 
 	req, err := http.NewRequest("GET", "/v999.0/version", nil)
 	c.Assert(err, check.IsNil)
-	req.Header.Set("User-Agent", "Docker-Client/999.0")
+	req.Header.Set("User-Agent", "Docker-Client/999.0 (os)")
 
 	res, err := client.Do(req)
 	c.Assert(res.StatusCode, check.Equals, http.StatusBadRequest)
diff --git a/integration-cli/docker_cli_config_test.go b/integration-cli/docker_cli_config_test.go
index 5ccd7af10e..82c133b2f7 100644
--- a/integration-cli/docker_cli_config_test.go
+++ b/integration-cli/docker_cli_config_test.go
@@ -7,7 +7,9 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
+	"runtime"
 
+	"github.com/docker/docker/autogen/dockerversion"
 	"github.com/docker/docker/pkg/homedir"
 	"github.com/go-check/check"
 )
@@ -50,6 +52,14 @@ func (s *DockerSuite) TestConfigHttpHeader(c *check.C) {
 	cmd := exec.Command(dockerBinary, "-H="+server.URL[7:], "ps")
 	out, _, _ := runCommandWithOutput(cmd)
 
+	if headers["User-Agent"] == nil {
+		c.Fatalf("Missing User-Agent: %q\nout:%v", headers, out)
+	}
+
+	if headers["User-Agent"][0] != "Docker-Client/"+dockerversion.VERSION+" ("+runtime.GOOS+")" {
+		c.Fatalf("Badly formatted User-Agent: %q\nout:%v", headers, out)
+	}
+
 	if headers["Myheader"] == nil || headers["Myheader"][0] != "MyValue" {
 		c.Fatalf("Missing/bad header: %q\nout:%v", headers, out)
 	}