@@ -133,23 +133,15 @@ func FromEnv(c *Client) error {

 			},

 			CheckRedirect: CheckRedirect,

 		}

+		WithHTTPClient(httpClient)(c)

 	}

 	host := os.Getenv("DOCKER_HOST")

 	if host != "" {

-		var err error

+		// WithHost will create an API client if it doesn't exist

 		if err := WithHost(host)(c); err != nil {

 			return err

 		}

-		httpClient, err = defaultHTTPClient(host)

-		if err != nil {

-			return err

-		}

-	}

-	if httpClient != nil {

-		if err := WithHTTPClient(httpClient)(c); err != nil {

-			return err

-		}

 	}

 	version := os.Getenv("DOCKER_API_VERSION")

 	if version != "" {

@@ -167,7 +159,8 @@ func WithVersion(version string) func(*Client) error {

 	}

 }

-// WithHost overrides the client host with the specified one

+// WithHost overrides the client host with the specified one, creating a new

+// http client if one doesn't exist

 func WithHost(host string) func(*Client) error {

 	return func(c *Client) error {

 		hostURL, err := ParseHostURL(host)

@@ -178,11 +171,17 @@ func WithHost(host string) func(*Client) error {

 		c.proto = hostURL.Scheme

 		c.addr = hostURL.Host

 		c.basePath = hostURL.Path

-		client, err := defaultHTTPClient(host)

-		if err != nil {

-			return err

+		if c.client == nil {

+			client, err := defaultHTTPClient(host)

+			if err != nil {

+				return err

+			}

+			return WithHTTPClient(client)(c)

+		}

+		if transport, ok := c.client.Transport.(*http.Transport); ok {

+			return sockets.ConfigureTransport(transport, c.proto, c.addr)

 		}

-		return WithHTTPClient(client)(c)

+		return fmt.Errorf("cannot apply host to http transport")

 	}

 }