diff --git a/binding/binding_test.go b/binding/binding_test.go
index baae2feb..827518f9 100644
--- a/binding/binding_test.go
+++ b/binding/binding_test.go
@@ -681,6 +681,15 @@ func TestHeaderBinding(t *testing.T) {
 	assert.NoError(t, h.Bind(req, &theader))
 	assert.Equal(t, 1000, theader.Limit)
 
+	req = requestWithBody("GET", "/", "")
+	req.Header.Add("fail", `{fail:fail}`)
+
+	type failStruct struct {
+		Fail map[string]interface{} `header:"fail"`
+	}
+
+	err := h.Bind(req, &failStruct{})
+	assert.Error(t, err)
 }
 
 func TestUriBinding(t *testing.T) {
diff --git a/binding/form_mapping.go b/binding/form_mapping.go
index ebf3b199..e5426819 100644
--- a/binding/form_mapping.go
+++ b/binding/form_mapping.go
@@ -38,8 +38,6 @@ type setter interface {
 
 type formSource map[string][]string
 
-var _ setter = formSource(nil)
-
 // TrySet tries to set a value by request's form source (like map[string][]string)
 func (form formSource) TrySet(value reflect.Value, field reflect.StructField, tagValue string, opt setOptions) (isSetted bool, err error) {
 	return setByForm(value, field, form, tagValue, opt)
diff --git a/binding/header.go b/binding/header.go
index 929ff618..ce40b15c 100644
--- a/binding/header.go
+++ b/binding/header.go
@@ -27,8 +27,6 @@ func mapHeader(ptr interface{}, h map[string][]string) error {
 
 type headerSource map[string][]string
 
-//var _ setter = headerSource(nil)
-
 func (hs headerSource) TrySet(value reflect.Value, field reflect.StructField, tagValue string, opt setOptions) (isSetted bool, err error) {
 	return setByForm(value, field, hs, textproto.CanonicalMIMEHeaderKey(tagValue), opt)
 }