diff --git a/.golangci.yml b/.golangci.yml
index 03671d9..ed8c8bd 100644
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -157,6 +157,7 @@ issues:
   exclude-rules:
     - path: _test\.go
       linters:
+        - dupl
         - gomnd
         - lll
         - bodyclose
diff --git a/v1/template.go b/v1/template.go
index 968df5c..ff973b2 100644
--- a/v1/template.go
+++ b/v1/template.go
@@ -87,8 +87,8 @@ func (b *TemplateButtons) UnmarshalJSON(value []byte) error {
 			btn = &PlainButton{}
 		case ButtonTypePhone:
 			btn = &PhoneButton{}
-		case ButtonTypeUrl:
-			btn = &UrlButton{}
+		case ButtonTypeURL:
+			btn = &URLButton{}
 		default:
 			return errors.New("undefined type of button")
 		}
@@ -139,7 +139,7 @@ type ButtonType string
 const (
 	ButtonTypePlain ButtonType = "plain"
 	ButtonTypePhone ButtonType = "phone"
-	ButtonTypeUrl   ButtonType = "url"
+	ButtonTypeURL   ButtonType = "url"
 )
 
 type PlainButton struct {
@@ -155,12 +155,12 @@ type PhoneButton struct {
 
 func (PhoneButton) ButtonType() ButtonType { return ButtonTypePhone }
 
-type UrlButton struct {
+type URLButton struct {
 	Label string `json:"label"`
-	Url   string `json:"url"`
+	URL   string `json:"url"`
 }
 
-func (UrlButton) ButtonType() ButtonType { return ButtonTypeUrl }
+func (URLButton) ButtonType() ButtonType { return ButtonTypeURL }
 
 type HeaderContent interface {
 	HeaderContentType() HeaderContentType
diff --git a/v1/template_test.go b/v1/template_test.go
index 43c1e73..7d94e3f 100644
--- a/v1/template_test.go
+++ b/v1/template_test.go
@@ -101,9 +101,9 @@ func TestUnmarshalInteractiveTemplate_TextHeader(t *testing.T) {
 	assert.Equal(t, "Hello, {{1}}!", h.Body)
 	assert.Equal(t, "Scooter", template.Footer)
 	assert.Equal(t, TemplateStatusApproved, template.VerificationStatus)
-	assert.Equal(t, ButtonTypeUrl, template.Buttons.Items[0].ButtonType())
-	assert.Equal(t, "222ddd", template.Buttons.Items[0].(*UrlButton).Url)
-	assert.Equal(t, "Go to website", template.Buttons.Items[0].(*UrlButton).Label)
+	assert.Equal(t, ButtonTypeURL, template.Buttons.Items[0].ButtonType())
+	assert.Equal(t, "222ddd", template.Buttons.Items[0].(*URLButton).URL)
+	assert.Equal(t, "Go to website", template.Buttons.Items[0].(*URLButton).Label)
 	assert.Equal(t, ButtonTypePlain, template.Buttons.Items[1].ButtonType())
 	assert.Equal(t, "Yes", template.Buttons.Items[1].(*PlainButton).Label)
 
@@ -148,9 +148,9 @@ func TestUnmarshalInteractiveTemplate_DocumentHeader(t *testing.T) {
 	assert.NotNil(t, template.Header.DocumentContent())
 	assert.Equal(t, "Scooter", template.Footer)
 	assert.Equal(t, TemplateStatusApproved, template.VerificationStatus)
-	assert.Equal(t, ButtonTypeUrl, template.Buttons.Items[0].ButtonType())
-	assert.Equal(t, "222ddd", template.Buttons.Items[0].(*UrlButton).Url)
-	assert.Equal(t, "Go to website", template.Buttons.Items[0].(*UrlButton).Label)
+	assert.Equal(t, ButtonTypeURL, template.Buttons.Items[0].ButtonType())
+	assert.Equal(t, "222ddd", template.Buttons.Items[0].(*URLButton).URL)
+	assert.Equal(t, "Go to website", template.Buttons.Items[0].(*URLButton).Label)
 	assert.Equal(t, ButtonTypePlain, template.Buttons.Items[1].ButtonType())
 	assert.Equal(t, "Yes", template.Buttons.Items[1].(*PlainButton).Label)
 
@@ -195,9 +195,9 @@ func TestUnmarshalInteractiveTemplate_ImageHeader(t *testing.T) {
 	assert.NotNil(t, template.Header.ImageContent())
 	assert.Equal(t, "Scooter", template.Footer)
 	assert.Equal(t, TemplateStatusApproved, template.VerificationStatus)
-	assert.Equal(t, ButtonTypeUrl, template.Buttons.Items[0].ButtonType())
-	assert.Equal(t, "222ddd", template.Buttons.Items[0].(*UrlButton).Url)
-	assert.Equal(t, "Go to website", template.Buttons.Items[0].(*UrlButton).Label)
+	assert.Equal(t, ButtonTypeURL, template.Buttons.Items[0].ButtonType())
+	assert.Equal(t, "222ddd", template.Buttons.Items[0].(*URLButton).URL)
+	assert.Equal(t, "Go to website", template.Buttons.Items[0].(*URLButton).Label)
 	assert.Equal(t, ButtonTypePlain, template.Buttons.Items[1].ButtonType())
 	assert.Equal(t, "Yes", template.Buttons.Items[1].(*PlainButton).Label)
 
@@ -242,9 +242,9 @@ func TestUnmarshalInteractiveTemplate_VideoHeader(t *testing.T) {
 	assert.NotNil(t, template.Header.VideoContent())
 	assert.Equal(t, "Scooter", template.Footer)
 	assert.Equal(t, TemplateStatusApproved, template.VerificationStatus)
-	assert.Equal(t, ButtonTypeUrl, template.Buttons.Items[0].ButtonType())
-	assert.Equal(t, "222ddd", template.Buttons.Items[0].(*UrlButton).Url)
-	assert.Equal(t, "Go to website", template.Buttons.Items[0].(*UrlButton).Label)
+	assert.Equal(t, ButtonTypeURL, template.Buttons.Items[0].ButtonType())
+	assert.Equal(t, "222ddd", template.Buttons.Items[0].(*URLButton).URL)
+	assert.Equal(t, "Go to website", template.Buttons.Items[0].(*URLButton).Label)
 	assert.Equal(t, ButtonTypePlain, template.Buttons.Items[1].ButtonType())
 	assert.Equal(t, "Yes", template.Buttons.Items[1].(*PlainButton).Label)
 
diff --git a/v1/template_type.go b/v1/template_type.go
index 10545da..bdbd4b4 100644
--- a/v1/template_type.go
+++ b/v1/template_type.go
@@ -17,14 +17,14 @@ var TypeMap = [][]byte{
 	TemplateTypeMedia: []byte("media"),
 }
 
-var UnknownTypeValue = errors.New("unknown TemplateType")
+var ErrUnknownTypeValue = errors.New("unknown TemplateType")
 
 func (e TemplateType) MarshalText() (text []byte, err error) {
 	if e.isValid() {
 		return TypeMap[e], nil
 	}
 
-	return nil, UnknownTypeValue
+	return nil, ErrUnknownTypeValue
 }
 
 func (e TemplateType) String() string {
@@ -32,7 +32,7 @@ func (e TemplateType) String() string {
 		return string(TypeMap[e])
 	}
 
-	panic(UnknownTypeValue)
+	panic(ErrUnknownTypeValue)
 }
 
 func (e *TemplateType) UnmarshalText(text []byte) error {
@@ -45,7 +45,7 @@ func (e *TemplateType) UnmarshalText(text []byte) error {
 		return nil
 	}
 
-	return UnknownTypeValue
+	return ErrUnknownTypeValue
 }
 
 func (e TemplateType) isValid() bool {