diff --git a/api.go b/api.go
index eb99230..5c2eb76 100644
--- a/api.go
+++ b/api.go
@@ -36,7 +36,7 @@ type HttpApi struct {
 	url         string
 	httpcli     gohttp.Client
 	Headers     http.Header
-	applyGlobal func(*RequestBuilder)
+	applyGlobal func(*requestBuilder)
 }
 
 // NewLocalApi tries to construct new HttpApi instance communicating with local
@@ -117,7 +117,7 @@ func NewURLApiWithClient(url string, c *gohttp.Client) (*HttpApi, error) {
 		url:         url,
 		httpcli:     *c,
 		Headers:     make(map[string][]string),
-		applyGlobal: func(*RequestBuilder) {},
+		applyGlobal: func(*requestBuilder) {},
 	}
 
 	// We don't support redirects.
@@ -134,7 +134,7 @@ func (api *HttpApi) WithOptions(opts ...caopts.ApiOption) (iface.CoreAPI, error)
 	}
 
 	subApi := *api
-	subApi.applyGlobal = func(req *RequestBuilder) {
+	subApi.applyGlobal = func(req *requestBuilder) {
 		if options.Offline {
 			req.Option("offline", options.Offline)
 		}
@@ -143,14 +143,14 @@ func (api *HttpApi) WithOptions(opts ...caopts.ApiOption) (iface.CoreAPI, error)
 	return &subApi, nil
 }
 
-func (api *HttpApi) Request(command string, args ...string) *RequestBuilder {
+func (api *HttpApi) Request(command string, args ...string) RequestBuilder {
 	headers := make(map[string]string)
 	if api.Headers != nil {
 		for k := range api.Headers {
 			headers[k] = api.Headers.Get(k)
 		}
 	}
-	return &RequestBuilder{
+	return &requestBuilder{
 		command: command,
 		args:    args,
 		shell:   api,
diff --git a/requestbuilder.go b/requestbuilder.go
index 2ffed7a..7012a89 100644
--- a/requestbuilder.go
+++ b/requestbuilder.go
@@ -12,8 +12,20 @@ import (
 	"github.com/ipfs/go-ipfs-files"
 )
 
-// RequestBuilder is an IPFS commands request builder.
-type RequestBuilder struct {
+type RequestBuilder interface {
+	Arguments(args ...string) RequestBuilder
+	BodyString(body string) RequestBuilder
+	BodyBytes(body []byte) RequestBuilder
+	Body(body io.Reader) RequestBuilder
+	FileBody(body io.Reader) RequestBuilder
+	Option(key string, value interface{}) RequestBuilder
+	Header(name, value string) RequestBuilder
+	Send(ctx context.Context) (*Response, error)
+	Exec(ctx context.Context, res interface{}) error
+}
+
+// requestBuilder is an IPFS commands request builder.
+type requestBuilder struct {
 	command string
 	args    []string
 	opts    map[string]string
@@ -24,29 +36,29 @@ type RequestBuilder struct {
 }
 
 // Arguments adds the arguments to the args.
-func (r *RequestBuilder) Arguments(args ...string) *RequestBuilder {
+func (r *requestBuilder) Arguments(args ...string) RequestBuilder {
 	r.args = append(r.args, args...)
 	return r
 }
 
 // BodyString sets the request body to the given string.
-func (r *RequestBuilder) BodyString(body string) *RequestBuilder {
+func (r *requestBuilder) BodyString(body string) RequestBuilder {
 	return r.Body(strings.NewReader(body))
 }
 
 // BodyBytes sets the request body to the given buffer.
-func (r *RequestBuilder) BodyBytes(body []byte) *RequestBuilder {
+func (r *requestBuilder) BodyBytes(body []byte) RequestBuilder {
 	return r.Body(bytes.NewReader(body))
 }
 
 // Body sets the request body to the given reader.
-func (r *RequestBuilder) Body(body io.Reader) *RequestBuilder {
+func (r *requestBuilder) Body(body io.Reader) RequestBuilder {
 	r.body = body
 	return r
 }
 
 // FileBody sets the request body to the given reader wrapped into multipartreader.
-func (r *RequestBuilder) FileBody(body io.Reader) *RequestBuilder {
+func (r *requestBuilder) FileBody(body io.Reader) RequestBuilder {
 	pr, _ := files.NewReaderPathFile("/dev/stdin", ioutil.NopCloser(body), nil)
 	d := files.NewMapDirectory(map[string]files.Node{"": pr})
 	r.body = files.NewMultiFileReader(d, false)
@@ -55,7 +67,7 @@ func (r *RequestBuilder) FileBody(body io.Reader) *RequestBuilder {
 }
 
 // Option sets the given option.
-func (r *RequestBuilder) Option(key string, value interface{}) *RequestBuilder {
+func (r *requestBuilder) Option(key string, value interface{}) RequestBuilder {
 	var s string
 	switch v := value.(type) {
 	case bool:
@@ -76,7 +88,7 @@ func (r *RequestBuilder) Option(key string, value interface{}) *RequestBuilder {
 }
 
 // Header sets the given header.
-func (r *RequestBuilder) Header(name, value string) *RequestBuilder {
+func (r *requestBuilder) Header(name, value string) RequestBuilder {
 	if r.headers == nil {
 		r.headers = make(map[string]string, 1)
 	}
@@ -85,7 +97,7 @@ func (r *RequestBuilder) Header(name, value string) *RequestBuilder {
 }
 
 // Send sends the request and return the response.
-func (r *RequestBuilder) Send(ctx context.Context) (*Response, error) {
+func (r *requestBuilder) Send(ctx context.Context) (*Response, error) {
 	r.shell.applyGlobal(r)
 
 	req := NewRequest(ctx, r.shell.url, r.command, r.args...)
@@ -96,7 +108,7 @@ func (r *RequestBuilder) Send(ctx context.Context) (*Response, error) {
 }
 
 // Exec sends the request a request and decodes the response.
-func (r *RequestBuilder) Exec(ctx context.Context, res interface{}) error {
+func (r *requestBuilder) Exec(ctx context.Context, res interface{}) error {
 	httpRes, err := r.Send(ctx)
 	if err != nil {
 		return err
@@ -112,3 +124,5 @@ func (r *RequestBuilder) Exec(ctx context.Context, res interface{}) error {
 
 	return httpRes.decode(res)
 }
+
+var _ RequestBuilder = &requestBuilder{}
diff --git a/response.go b/response.go
index 2d6af49..db22a66 100644
--- a/response.go
+++ b/response.go
@@ -97,7 +97,7 @@ func (r *Request) Send(c *http.Client) (*Response, error) {
 
 	req = req.WithContext(r.Ctx)
 
-	// Add any headers that were supplied via the RequestBuilder.
+	// Add any headers that were supplied via the requestBuilder.
 	for k, v := range r.Headers {
 		req.Header.Add(k, v)
 	}