diff --git a/auth_test.go b/auth_test.go
index 8b58e6f..37e9067 100644
--- a/auth_test.go
+++ b/auth_test.go
@@ -19,12 +19,12 @@ func TestGetAuthorization(t *testing.T) {
 
 	a, err := c.GetAuthorization(testAuthID)
 	if err != nil || a.ID != testAuthID {
-		t.Errorf("GetAuthorization failed for ID=" + testAuthID)
+		t.Errorf("GetAuthorization failed for ID=%s", testAuthID)
 	}
 
 	a, err = c.GetAuthorization(testFakeAuthID)
 	if err == nil {
-		t.Errorf("GetAuthorization must return error for ID=" + testFakeAuthID)
+		t.Errorf("GetAuthorization must return error for ID=%s", testFakeAuthID)
 	}
 }
 
diff --git a/client.go b/client.go
index 442ab5c..9beee97 100644
--- a/client.go
+++ b/client.go
@@ -47,6 +47,12 @@ func (c *Client) SetAccessToken(token string) error {
 // unmarshaled into v, or if v is an io.Writer, the response will
 // be written to it without decoding
 func (c *Client) Send(req *http.Request, v interface{}) error {
+	var (
+		err  error
+		resp *http.Response
+		data []byte
+	)
+
 	// Set default headers
 	req.Header.Set("Accept", "application/json")
 	req.Header.Set("Accept-Language", "en_US")
@@ -56,7 +62,7 @@ func (c *Client) Send(req *http.Request, v interface{}) error {
 		req.Header.Set("Content-type", "application/json")
 	}
 
-	resp, err := c.client.Do(req)
+	resp, err = c.client.Do(req)
 	c.log(req, resp)
 
 	if err != nil {
@@ -66,7 +72,7 @@ func (c *Client) Send(req *http.Request, v interface{}) error {
 
 	if resp.StatusCode < 200 || resp.StatusCode > 299 {
 		errResp := &ErrorResponse{Response: resp}
-		data, err := ioutil.ReadAll(resp.Body)
+		data, err = ioutil.ReadAll(resp.Body)
 
 		if err == nil && len(data) > 0 {
 			json.Unmarshal(data, errResp)
@@ -90,10 +96,19 @@ func (c *Client) Send(req *http.Request, v interface{}) error {
 }
 
 // SendWithAuth makes a request to the API and apply OAuth2 header automatically.
-// If the access token soon to be expired, it will try to get a new one before
+// If the access token soon to be expired or already expired, it will try to get a new one before
 // making the main request
+// client.Token will be updated when changed
 func (c *Client) SendWithAuth(req *http.Request, v interface{}) error {
 	if c.Token != nil {
+		if c.Token.ExpiresIn < RequestNewTokenBeforeExpiresIn {
+			// c.Token willbe updated in GetAccessToken call
+			_, err := c.GetAccessToken()
+			if err != nil {
+				return err
+			}
+		}
+
 		req.Header.Set("Authorization", "Bearer "+c.Token.Token)
 	}
 
diff --git a/client_test.go b/client_test.go
index eb37983..04a70b6 100644
--- a/client_test.go
+++ b/client_test.go
@@ -27,6 +27,6 @@ func TestNewClient(t *testing.T) {
 
 	_, err = NewClient(testClientID, testSecret, APIBaseSandBox)
 	if err != nil {
-		t.Errorf("NewClient() must not return error for valid creds: " + err.Error())
+		t.Errorf("NewClient() must not return error for valid creds: %s", err.Error())
 	}
 }
diff --git a/identity_test.go b/identity_test.go
index 6336e9b..9593b6d 100644
--- a/identity_test.go
+++ b/identity_test.go
@@ -26,6 +26,6 @@ func TestGetUserInfo(t *testing.T) {
 
 	u, err := c.GetUserInfo("openid")
 	if u.ID != testUserID || err != nil {
-		t.Errorf("GetUserInfo must return valid test ID=" + testUserID)
+		t.Errorf("GetUserInfo must return valid test ID=%s", testUserID)
 	}
 }
diff --git a/order_test.go b/order_test.go
index 14e9870..31829b4 100644
--- a/order_test.go
+++ b/order_test.go
@@ -11,12 +11,12 @@ func TestGetOrder(t *testing.T) {
 
 	o, err := c.GetOrder(testOrderID)
 	if err != nil || o.ID != testOrderID {
-		t.Errorf("GetOrder failed for ID=" + testOrderID)
+		t.Errorf("GetOrder failed for ID=%s", testOrderID)
 	}
 
 	o, err = c.GetOrder(testFakeOrderID)
 	if err == nil {
-		t.Errorf("GetOrder must return error for ID=" + testFakeOrderID)
+		t.Errorf("GetOrder must return error for ID=%s", testFakeOrderID)
 	}
 }
 
diff --git a/payment_test.go b/payment_test.go
index 5fd8f8c..ee3e2ac 100644
--- a/payment_test.go
+++ b/payment_test.go
@@ -2,7 +2,6 @@ package paypalsdk
 
 import (
 	"fmt"
-	"strconv"
 	"testing"
 )
 
@@ -42,7 +41,7 @@ func TestGetPayments(t *testing.T) {
 	payments, _ := c.GetPayments()
 
 	if len(payments) != 2 {
-		t.Errorf("2 payments must be returned for GetPayments. Returned: " + strconv.Itoa(len(payments)))
+		t.Errorf("2 payments must be returned for GetPayments. Returned: %d", len(payments))
 	}
 }
 
diff --git a/sale_test.go b/sale_test.go
index 0f6093e..544e3a6 100644
--- a/sale_test.go
+++ b/sale_test.go
@@ -11,7 +11,7 @@ func TestGetSale(t *testing.T) {
 
 	_, err := c.GetSale(testSaleID)
 	if err == nil {
-		t.Errorf("404 must be returned for ID=" + testSaleID)
+		t.Errorf("404 must be returned for ID=%s", testSaleID)
 	} else {
 		fmt.Println(err.Error())
 	}
@@ -23,14 +23,14 @@ func TestRefundSale(t *testing.T) {
 
 	_, err := c.RefundSale(testSaleID, nil)
 	if err == nil {
-		t.Errorf("404 must be returned for ID=" + testSaleID)
+		t.Errorf("404 must be returned for ID=%s", testSaleID)
 	} else {
 		fmt.Println(err.Error())
 	}
 
 	_, err = c.RefundSale(testSaleID, &Amount{Total: "7.00", Currency: "USD"})
 	if err == nil {
-		t.Errorf("404 must be returned for ID=" + testSaleID)
+		t.Errorf("404 must be returned for ID=%s", testSaleID)
 	} else {
 		fmt.Println(err.Error())
 	}
@@ -42,7 +42,7 @@ func TestGetRefund(t *testing.T) {
 
 	_, err := c.GetRefund("1")
 	if err == nil {
-		t.Errorf("404 must be returned for ID=" + testSaleID)
+		t.Errorf("404 must be returned for ID=%s", testSaleID)
 	} else {
 		fmt.Println(err.Error())
 	}
diff --git a/types.go b/types.go
index f4c8096..00b53c7 100644
--- a/types.go
+++ b/types.go
@@ -13,6 +13,9 @@ const (
 
 	// APIBaseLive points to the live version of the API
 	APIBaseLive = "https://api.paypal.com"
+
+	// RequestNewTokenBeforeExpiresIn is used by SendWithAuth and try to get new Token when it's about to expire
+	RequestNewTokenBeforeExpiresIn = 60
 )
 
 type (