diff --git a/unmarshal.go b/unmarshal.go
index bd9f215..16caddb 100644
--- a/unmarshal.go
+++ b/unmarshal.go
@@ -77,7 +77,12 @@ func Unmarshal(data []byte, v interface{}) (err error) {
 			value = parseStructureType(result, field.Type())
 		} else {
 			// set field value depend on it's data type
-			value = parseDataType(result, field.Kind().String())
+			value = parseDataType(result, field.Type().String())
+		}
+
+		// maybe it is a custom type, use json.unmarshal
+		if value == nil {
+			value = unmarshalGeneric(result.Raw, field)
 		}
 
 		if v != nil {
@@ -130,3 +135,12 @@ func unmarshalStruct(raw string, field reflect.Type) interface{} {
 
 	return reflect.Indirect(reflect.ValueOf(v)).Interface()
 }
+
+func unmarshalGeneric(raw string, field reflect.Value) interface{} {
+	err := json.Unmarshal([]byte(raw), field.Addr().Interface())
+	if err != nil {
+		panic(err)
+	}
+
+	return reflect.Indirect(field).Interface()
+}
diff --git a/unmarshal_test.go b/unmarshal_test.go
index d665ead..04b9c76 100644
--- a/unmarshal_test.go
+++ b/unmarshal_test.go
@@ -1,13 +1,110 @@
 package njson
 
 import (
+	"encoding/json"
 	json2 "encoding/json"
+	"fmt"
 	"testing"
 	"time"
 
 	"github.com/google/go-cmp/cmp"
 )
 
+type CustomType string
+type CustomUnmarshalerType string
+
+// Implements Unmarshaler
+func (ct *CustomUnmarshalerType) UnmarshalJSON(data []byte) error {
+	var s string
+	if err := json.Unmarshal(data, &s); err != nil {
+		return err
+	}
+	// add a mark to control it later
+	*ct = CustomUnmarshalerType(fmt.Sprintf("unmarshaler:%s", s))
+	return nil
+}
+
+func TestCustomTypeUnmarshal(t *testing.T) {
+
+	type CustomStruct struct {
+		Normal string     `njson:"inner.nested"`
+		Custom CustomType `njson:"custom"`
+	}
+
+	json := `{"custom": "value", "inner": { "nested": "nestedValue"}}`
+
+	var actual CustomStruct
+
+	if err := Unmarshal([]byte(json), &actual); err != nil {
+		t.Errorf("error should be nil: %v", err)
+	}
+
+	expected := CustomStruct{
+		Normal: "nestedValue",
+		Custom: CustomType("value"),
+	}
+
+	diff := cmp.Diff(expected, actual)
+
+	if diff != "" {
+		t.Errorf(diff)
+	}
+}
+
+func TestCustomTypeUnmarshaler(t *testing.T) {
+
+	type CustomStruct struct {
+		Normal string                `njson:"inner.nested"`
+		Custom CustomUnmarshalerType `njson:"custom"`
+	}
+
+	json := `{"custom": "value", "inner": { "nested": "nestedValue"}}`
+
+	var actual CustomStruct
+
+	if err := Unmarshal([]byte(json), &actual); err != nil {
+		t.Errorf("error should be nil: %v", err)
+	}
+
+	expected := CustomStruct{
+		Normal: "nestedValue",
+		Custom: CustomUnmarshalerType("unmarshaler:value"),
+	}
+
+	diff := cmp.Diff(expected, actual)
+
+	if diff != "" {
+		t.Errorf(diff)
+	}
+}
+
+func TestCustomTypeUnmarshalerNested(t *testing.T) {
+
+	type CustomStruct struct {
+		Normal string                `njson:"inner.nested"`
+		Custom CustomUnmarshalerType `njson:"custom.key.nested"`
+	}
+
+	json := `{"custom": { "key": {"nested": "value"} }, "inner": { "nested": "nestedValue"}}`
+
+	var actual CustomStruct
+
+	if err := Unmarshal([]byte(json), &actual); err != nil {
+		t.Errorf("error should be nil: %v", err)
+	}
+
+	expected := CustomStruct{
+		Normal: "nestedValue",
+		Custom: CustomUnmarshalerType("unmarshaler:value"),
+	}
+
+	diff := cmp.Diff(expected, actual)
+
+	if diff != "" {
+		t.Errorf(diff)
+	}
+}
+
 func TestUnmarshalInvalidJson(t *testing.T) {
 	json := `
 	BAD JSON %% @