diff --git a/_example/i18n/de.json b/_example/i18n/de.json
new file mode 100644
index 0000000..71231d2
--- /dev/null
+++ b/_example/i18n/de.json
@@ -0,0 +1,4 @@
+{
+  "welcome": "hallo",
+  "welcomeWithName": "hallo {{ .name }}"
+}
diff --git a/_example/i18n/en.json b/_example/i18n/en.json
new file mode 100644
index 0000000..120a5be
--- /dev/null
+++ b/_example/i18n/en.json
@@ -0,0 +1,4 @@
+{
+  "welcome": "hello",
+  "welcomeWithName": "hello {{ .name }}"
+}
diff --git a/_example/i18n/fr.json b/_example/i18n/fr.json
new file mode 100644
index 0000000..e07d847
--- /dev/null
+++ b/_example/i18n/fr.json
@@ -0,0 +1,4 @@
+{
+    "welcome": "bonjour",
+    "welcomeWithName": "bonjour {{ .name }}"
+}
\ No newline at end of file
diff --git a/_example/i18n/zh.json b/_example/i18n/zh.json
new file mode 100644
index 0000000..caf17e0
--- /dev/null
+++ b/_example/i18n/zh.json
@@ -0,0 +1,4 @@
+{
+    "welcomeWithNameAndFood":"欢迎宝贝{{ .name }}, 我喜欢吃 {{ .food }}",
+    "welcome": "欢迎"
+}
\ No newline at end of file
diff --git a/_example/main.go b/_example/main.go
index d94063a..c03560d 100644
--- a/_example/main.go
+++ b/_example/main.go
@@ -1,12 +1,14 @@
 package main
 
 import (
+	"encoding/json"
 	"log"
 	"net/http"
 
 	ginI18n "github.com/gin-contrib/i18n"
 	"github.com/gin-gonic/gin"
 	"github.com/nicksnyder/go-i18n/v2/i18n"
+	"golang.org/x/text/language"
 )
 
 func main() {
@@ -15,7 +17,13 @@ func main() {
 	router := gin.New()
 
 	// apply i18n middleware
-	router.Use(ginI18n.Localize())
+	r.Use(ginI18n.Localize(ginI18n.WithBundle(&ginI18n.BundleCfg{
+		RootPath:         "./i18n",
+		AcceptLanguage:   []language.Tag{language.Chinese, language.English},
+		DefaultLanguage:  language.English,
+		FormatBundleFile: "json",
+		UnmarshalFunc:    json.Unmarshal,
+	})))
 
 	router.GET("/", func(context *gin.Context) {
 		context.String(http.StatusOK, ginI18n.MustGetMessage("welcome"))
diff --git a/ginI18n.go b/ginI18n.go
index 6c8c686..dc83aa0 100644
--- a/ginI18n.go
+++ b/ginI18n.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"reflect"
 
 	"github.com/gin-gonic/gin"
 	"github.com/nicksnyder/go-i18n/v2/i18n"
@@ -50,6 +51,28 @@ func (i *ginI18nImpl) setCurrentContext(ctx context.Context) {
 	i.currentContext = ctx.(*gin.Context)
 }
 
+func (ginI18nImpl) setCustomerBundle(cfg *BundleCfg) {
+	if !reflect.DeepEqual(cfg.DefaultLanguage, language.Tag{}) {
+		defaultBundleConfig.DefaultLanguage = cfg.DefaultLanguage
+	}
+
+	if len(cfg.AcceptLanguage) != 0 {
+		defaultBundleConfig.AcceptLanguage = cfg.AcceptLanguage
+	}
+
+	if cfg.FormatBundleFile != "" {
+		defaultBundleConfig.FormatBundleFile = cfg.FormatBundleFile
+	}
+
+	if cfg.RootPath != "" {
+		defaultBundleConfig.RootPath = cfg.RootPath
+	}
+
+	if cfg.UnmarshalFunc != nil {
+		defaultBundleConfig.UnmarshalFunc = cfg.UnmarshalFunc
+	}
+}
+
 func (i *ginI18nImpl) setBundle(cfg *BundleCfg) {
 	bundle := i18n.NewBundle(cfg.DefaultLanguage)
 	bundle.RegisterUnmarshalFunc(cfg.FormatBundleFile, cfg.UnmarshalFunc)
diff --git a/i18n.go b/i18n.go
index fa803bd..2c14907 100644
--- a/i18n.go
+++ b/i18n.go
@@ -12,13 +12,14 @@ func newI18n(opts ...Option) {
 	ins := &ginI18nImpl{
 		getLngHandler: defaultGetLngHandler,
 	}
-	ins.setBundle(defaultBundleConfig)
 
 	// overwrite default value by options
 	for _, opt := range opts {
 		opt(ins)
 	}
 
+	ins.setBundle(defaultBundleConfig)
+
 	atI18n = ins
 }
 
diff --git a/i18n_test.go b/i18n_test.go
index 1488804..2102a1d 100644
--- a/i18n_test.go
+++ b/i18n_test.go
@@ -1,6 +1,7 @@
 package i18n
 
 import (
+	"encoding/json"
 	"net/http"
 	"net/http/httptest"
 	"testing"
@@ -14,6 +15,55 @@ func init() {
 	gin.SetMode(gin.ReleaseMode)
 }
 
+func newPartCustomerConfigServer() *gin.Engine {
+	router := gin.New()
+	router.Use(Localize(WithBundle(&BundleCfg{
+		RootPath:         "./_example/i18n",
+		FormatBundleFile: "json",
+	})))
+
+	router.GET("/", func(context *gin.Context) {
+		context.String(http.StatusOK, MustGetMessage("welcome"))
+	})
+
+	router.GET("/:name", func(context *gin.Context) {
+		context.String(http.StatusOK, MustGetMessage(&i18n.LocalizeConfig{
+			MessageID: "welcomeWithName",
+			TemplateData: map[string]string{
+				"name": context.Param("name"),
+			},
+		}))
+	})
+
+	return router
+}
+func newCustomerServer() *gin.Engine {
+	router := gin.New()
+	router.Use(Localize(WithBundle(&BundleCfg{
+		RootPath:         "./_example/i18n",
+		AcceptLanguage:   []language.Tag{language.Chinese, language.English},
+		DefaultLanguage:  language.English,
+		FormatBundleFile: "json",
+		UnmarshalFunc:    json.Unmarshal,
+	})))
+
+	router.GET("/", func(context *gin.Context) {
+		context.String(http.StatusOK, MustGetMessage("welcome"))
+	})
+
+	router.GET("/:name/:food", func(context *gin.Context) {
+		context.String(http.StatusOK, MustGetMessage(&i18n.LocalizeConfig{
+			MessageID: "welcomeWithNameAndFood",
+			TemplateData: map[string]string{
+				"name": context.Param("name"),
+				"food": context.Param("food"),
+			},
+		}))
+	})
+
+	return router
+}
+
 // newServer ...
 func newServer() *gin.Engine {
 	router := gin.New()
@@ -35,6 +85,39 @@ func newServer() *gin.Engine {
 	return router
 }
 
+func makeRequest3(
+	lng language.Tag,
+	name string,
+) string {
+	path := "/" + name
+	req, _ := http.NewRequest("GET", path, nil)
+	req.Header.Add("Accept-Language", lng.String())
+
+	// Perform the request
+	w := httptest.NewRecorder()
+	r := newPartCustomerConfigServer()
+	r.ServeHTTP(w, req)
+
+	return w.Body.String()
+}
+
+func makeRequest2(
+	lng language.Tag,
+	name string,
+	food string,
+) string {
+	path := "/" + name + "/" + food
+	req, _ := http.NewRequest("GET", path, nil)
+	req.Header.Add("Accept-Language", lng.String())
+
+	// Perform the request
+	w := httptest.NewRecorder()
+	r := newCustomerServer()
+	r.ServeHTTP(w, req)
+
+	return w.Body.String()
+}
+
 // makeRequest ...
 func makeRequest(
 	lng language.Tag,
@@ -159,3 +242,78 @@ func TestI18nFR(t *testing.T) {
 		})
 	}
 }
+
+func TestCustomerI18n(t *testing.T) {
+	type args struct {
+		lng  language.Tag
+		name string
+		food string
+	}
+	tests := []struct {
+		name string
+		args args
+		want string
+	}{
+		{
+			name: "1st",
+			args: args{
+				name: "watch",
+				food: "apple",
+				lng:  language.Chinese,
+			},
+			want: "欢迎宝贝watch, 我喜欢吃 apple",
+		},
+		{
+			name: "2nd",
+			args: args{
+				name: "issues",
+				food: "orange",
+				lng:  language.English,
+			},
+			want: "welcome my baby issues，I like orange",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := makeRequest2(tt.args.lng, tt.args.name, tt.args.food); got != tt.want {
+				t.Errorf("makeRequest2() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestPartCustomerConfigI18n(t *testing.T) {
+	type args struct {
+		lng  language.Tag
+		name string
+	}
+	tests := []struct {
+		name string
+		args args
+		want string
+	}{
+		{
+			name: "hello world",
+			args: args{
+				name: "",
+				lng:  language.English,
+			},
+			want: "hello",
+		},
+		{
+			name: "hello alex",
+			args: args{
+				name: "alex",
+				lng:  language.English,
+			},
+			want: "hello alex",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := makeRequest3(tt.args.lng, tt.args.name); got != tt.want {
+				t.Errorf("makeRequest3() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
diff --git a/interface.go b/interface.go
index 8650b4f..34029ce 100644
--- a/interface.go
+++ b/interface.go
@@ -11,5 +11,6 @@ type GinI18n interface {
 
 	setCurrentContext(ctx context.Context)
 	setBundle(cfg *BundleCfg)
+	setCustomerBundle(cfg *BundleCfg)
 	setGetLngHandler(handler GetLngHandler)
 }
diff --git a/option.go b/option.go
index 794e459..c1d0b6b 100644
--- a/option.go
+++ b/option.go
@@ -17,7 +17,7 @@ type BundleCfg struct {
 // WithBundle ...
 func WithBundle(config *BundleCfg) Option {
 	return func(g GinI18n) {
-		g.setBundle(config)
+		g.setCustomerBundle(config)
 	}
 }