@@ -234,6 +234,14 @@ func WithHTTPHeaders(headers map[string]string) func(*Client) error {

 	}

 }

+// WithScheme overrides the client scheme with the specified one

+func WithScheme(scheme string) func(*Client) error {

+	return func(c *Client) error {

+		c.scheme = scheme

+		return nil

+	}

+}

+

 // NewClientWithOpts initializes a new API client with default values. It takes functors

 // to modify values when creating it, like `NewClientWithOpts(WithVersion(…))`

 // It also initializes the custom http headers to add to each request.

@@ -249,7 +257,6 @@ func NewClientWithOpts(ops ...func(*Client) error) (*Client, error) {

 	c := &Client{

 		host:    DefaultDockerHost,

 		version: api.DefaultVersion,

-		scheme:  "http",

 		client:  client,

 		proto:   defaultProto,

 		addr:    defaultAddr,

@@ -264,14 +271,18 @@ func NewClientWithOpts(ops ...func(*Client) error) (*Client, error) {

 	if _, ok := c.client.Transport.(http.RoundTripper); !ok {

 		return nil, fmt.Errorf("unable to verify TLS configuration, invalid transport %v", c.client.Transport)

 	}

-	tlsConfig := resolveTLSConfig(c.client.Transport)

-	if tlsConfig != nil {

-		// TODO(stevvooe): This isn't really the right way to write clients in Go.

-		// `NewClient` should probably only take an `*http.Client` and work from there.

-		// Unfortunately, the model of having a host-ish/url-thingy as the connection

-		// string has us confusing protocol and transport layers. We continue doing

-		// this to avoid breaking existing clients but this should be addressed.

-		c.scheme = "https"

+	if c.scheme == "" {

+		c.scheme = "http"

+

+		tlsConfig := resolveTLSConfig(c.client.Transport)

+		if tlsConfig != nil {

+			// TODO(stevvooe): This isn't really the right way to write clients in Go.

+			// `NewClient` should probably only take an `*http.Client` and work from there.

+			// Unfortunately, the model of having a host-ish/url-thingy as the connection

+			// string has us confusing protocol and transport layers. We continue doing

+			// this to avoid breaking existing clients but this should be addressed.

+			c.scheme = "https"

+		}

 	}

 	return c, nil