diff --git a/appstore/validator.go b/appstore/validator.go
index 1a8c2fd..1e4af86 100644
--- a/appstore/validator.go
+++ b/appstore/validator.go
@@ -2,11 +2,11 @@ package appstore
 
 import (
 	"bytes"
+	"context"
 	"encoding/json"
 	"errors"
 	"io/ioutil"
 	"net/http"
-	"time"
 )
 
 const (
@@ -18,14 +18,9 @@ const (
 	ContentType string = "application/json; charset=utf-8"
 )
 
-// Config is a configuration to initialize client
-type Config struct {
-	TimeOut time.Duration
-}
-
 // IAPClient is an interface to call validation API in App Store
 type IAPClient interface {
-	Verify(IAPRequest, interface{}) error
+	Verify(ctx context.Context, reqBody IAPRequest, resp interface{}) error
 }
 
 // Client implements IAPClient
@@ -98,7 +93,7 @@ func NewWithClient(client *http.Client) *Client {
 }
 
 // Verify sends receipts and gets validation result
-func (c *Client) Verify(reqBody IAPRequest, result interface{}) error {
+func (c *Client) Verify(ctx context.Context, reqBody IAPRequest, result interface{}) error {
 	b := new(bytes.Buffer)
 	json.NewEncoder(b).Encode(reqBody)
 
@@ -107,15 +102,16 @@ func (c *Client) Verify(reqBody IAPRequest, result interface{}) error {
 		return err
 	}
 	req.Header.Set("Content-Type", ContentType)
+	req = req.WithContext(ctx)
 	resp, err := c.httpCli.Do(req)
 	if err != nil {
 		return err
 	}
 	defer resp.Body.Close()
-	return c.parseResponse(resp, result, reqBody)
+	return c.parseResponse(resp, result, ctx, reqBody)
 }
 
-func (c *Client) parseResponse(resp *http.Response, result interface{}, reqBody IAPRequest) error {
+func (c *Client) parseResponse(resp *http.Response, result interface{}, ctx context.Context, reqBody IAPRequest) error {
 	// Read the body now so that we can unmarshal it twice
 	buf, err := ioutil.ReadAll(resp.Body)
 	if err != nil {
@@ -142,6 +138,7 @@ func (c *Client) parseResponse(resp *http.Response, result interface{}, reqBody
 			return err
 		}
 		req.Header.Set("Content-Type", ContentType)
+		req = req.WithContext(ctx)
 		resp, err := c.httpCli.Do(req)
 		if err != nil {
 			return err
diff --git a/appstore/validator_test.go b/appstore/validator_test.go
index e7c8972..408bbc2 100644
--- a/appstore/validator_test.go
+++ b/appstore/validator_test.go
@@ -1,6 +1,7 @@
 package appstore
 
 import (
+	"context"
 	"errors"
 	"io/ioutil"
 	"net/http"
@@ -128,10 +129,31 @@ func TestVerifyTimeout(t *testing.T) {
 		ReceiptData: "dummy data",
 	}
 	result := &IAPResponse{}
-	err := client.Verify(req, result)
+	ctx := context.Background()
+	err := client.Verify(ctx, req, result)
 	if err == nil {
 		t.Errorf("error should be occurred because of timeout")
 	}
+	t.Log(err)
+}
+
+func TestVerifyWithCancel(t *testing.T) {
+	client := New()
+
+	req := IAPRequest{
+		ReceiptData: "dummy data",
+	}
+	result := &IAPResponse{}
+	ctx, cancelFunc := context.WithCancel(context.Background())
+	go func() {
+		time.Sleep(10 * time.Millisecond)
+		cancelFunc()
+	}()
+	err := client.Verify(ctx, req, result)
+	if err == nil {
+		t.Errorf("error should be occurred because of context cancel")
+	}
+	t.Log(err)
 }
 
 func TestVerifyBadURL(t *testing.T) {
@@ -142,7 +164,8 @@ func TestVerifyBadURL(t *testing.T) {
 		ReceiptData: "dummy data",
 	}
 	result := &IAPResponse{}
-	err := client.Verify(req, result)
+	ctx := context.Background()
+	err := client.Verify(ctx, req, result)
 	if err == nil {
 		t.Errorf("error should be occurred because the server is not real")
 	}
@@ -195,7 +218,8 @@ func TestResponses(t *testing.T) {
 			client.SandboxURL = tc.sandboxServ.URL
 		}
 
-		err := client.Verify(req, result)
+		ctx := context.Background()
+		err := client.Verify(ctx, req, result)
 		if err != nil {
 			t.Errorf("Test case %d - %s", i, err.Error())
 		}
@@ -233,7 +257,8 @@ func TestErrors(t *testing.T) {
 		defer tc.testServer.Close()
 		client.ProductionURL = tc.testServer.URL
 
-		err := client.Verify(req, result)
+		ctx := context.Background()
+		err := client.Verify(ctx, req, result)
 		if err == nil {
 			t.Errorf("Test case %d - expected error to be not nil since the sandbox is not responding", i)
 		}
@@ -244,7 +269,8 @@ func TestCannotReadBody(t *testing.T) {
 	client := New()
 	testResponse := http.Response{Body: ioutil.NopCloser(errReader(0))}
 
-	if client.parseResponse(&testResponse, IAPResponse{}, IAPRequest{}) == nil {
+	ctx := context.Background()
+	if client.parseResponse(&testResponse, IAPResponse{}, ctx, IAPRequest{}) == nil {
 		t.Errorf("expected redirectToSandbox to fail to read the body")
 	}
 }
@@ -253,7 +279,8 @@ func TestCannotUnmarshalBody(t *testing.T) {
 	client := New()
 	testResponse := http.Response{Body: ioutil.NopCloser(strings.NewReader(`{"status": true}`))}
 
-	if client.parseResponse(&testResponse, StatusResponse{}, IAPRequest{}) == nil {
+	ctx := context.Background()
+	if client.parseResponse(&testResponse, StatusResponse{}, ctx, IAPRequest{}) == nil {
 		t.Errorf("expected redirectToSandbox to fail to unmarshal the data")
 	}
 }