diff --git a/README.md b/README.md
index 2f94d05..9b1b466 100644
--- a/README.md
+++ b/README.md
@@ -1,9 +1,9 @@
 # GZIP gin's middleware
 
-[![Run Tests](https://github.com/gin-contrib/gzip/actions/workflows/go.yml/badge.svg)](https://github.com/gin-contrib/gzip/actions/workflows/go.yml)
+[![Run Tests](https://github.com/lawyzheng/gzip/actions/workflows/go.yml/badge.svg)](https://github.com/lawyzheng/gzip/actions/workflows/go.yml)
 [![codecov](https://codecov.io/gh/gin-contrib/gzip/branch/master/graph/badge.svg)](https://codecov.io/gh/gin-contrib/gzip)
-[![Go Report Card](https://goreportcard.com/badge/github.com/gin-contrib/gzip)](https://goreportcard.com/report/github.com/gin-contrib/gzip)
-[![GoDoc](https://godoc.org/github.com/gin-contrib/gzip?status.svg)](https://godoc.org/github.com/gin-contrib/gzip)
+[![Go Report Card](https://goreportcard.com/badge/github.com/lawyzheng/gzip)](https://goreportcard.com/report/github.com/lawyzheng/gzip)
+[![GoDoc](https://godoc.org/github.com/lawyzheng/gzip?status.svg)](https://godoc.org/github.com/lawyzheng/gzip)
 [![Join the chat at https://gitter.im/gin-gonic/gin](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/gin-gonic/gin)
 
 Gin middleware to enable `GZIP` support.
@@ -13,13 +13,13 @@ Gin middleware to enable `GZIP` support.
 Download and install it:
 
 ```sh
-go get github.com/gin-contrib/gzip
+go get github.com/lawyzheng/gzip
 ```
 
 Import it in your code:
 
 ```go
-import "github.com/gin-contrib/gzip"
+import "github.com/lawyzheng/gzip"
 ```
 
 Canonical example:
@@ -32,7 +32,7 @@ import (
   "net/http"
   "time"
 
-  "github.com/gin-contrib/gzip"
+  "github.com/lawyzheng/gzip"
   "github.com/gin-gonic/gin"
 )
 
@@ -60,7 +60,7 @@ import (
   "net/http"
   "time"
 
-  "github.com/gin-contrib/gzip"
+  "github.com/lawyzheng/gzip"
   "github.com/gin-gonic/gin"
 )
 
@@ -88,7 +88,7 @@ import (
   "net/http"
   "time"
 
-  "github.com/gin-contrib/gzip"
+  "github.com/lawyzheng/gzip"
   "github.com/gin-gonic/gin"
 )
 
@@ -116,7 +116,7 @@ import (
   "net/http"
   "time"
 
-  "github.com/gin-contrib/gzip"
+  "github.com/lawyzheng/gzip"
   "github.com/gin-gonic/gin"
 )
 
diff --git a/example/example.go b/example/example.go
index e0a930f..59bb4ed 100644
--- a/example/example.go
+++ b/example/example.go
@@ -6,8 +6,8 @@ import (
 	"net/http"
 	"time"
 
-	"github.com/gin-contrib/gzip"
 	"github.com/gin-gonic/gin"
+	"github.com/lawyzheng/gzip"
 )
 
 func main() {
diff --git a/go.mod b/go.mod
index e7135a6..f0108e5 100644
--- a/go.mod
+++ b/go.mod
@@ -1,4 +1,4 @@
-module github.com/gin-contrib/gzip
+module github.com/lawyzheng/gzip
 
 require (
 	github.com/gin-gonic/gin v1.8.1
diff --git a/gzip.go b/gzip.go
index 529c62d..e07fbc2 100644
--- a/gzip.go
+++ b/gzip.go
@@ -19,7 +19,8 @@ func Gzip(level int, options ...Option) gin.HandlerFunc {
 
 type gzipWriter struct {
 	gin.ResponseWriter
-	writer *gzip.Writer
+	writer  *gzip.Writer
+	gzipped bool
 }
 
 func (g *gzipWriter) WriteString(s string) (int, error) {
@@ -28,12 +29,28 @@ func (g *gzipWriter) WriteString(s string) (int, error) {
 }
 
 func (g *gzipWriter) Write(data []byte) (int, error) {
+	g.gzipped = g.isGzipped(data) || g.gzipped
+	if g.gzipped {
+		return g.ResponseWriter.Write(data)
+	}
+
+	g.Header().Set("Content-Encoding", "gzip")
+	g.Header().Set("Vary", "Accept-Encoding")
 	g.Header().Del("Content-Length")
 	return g.writer.Write(data)
 }
 
 // Fix: https://github.com/mholt/caddy/issues/38
 func (g *gzipWriter) WriteHeader(code int) {
+	g.Header().Set("Content-Encoding", "gzip")
+	g.Header().Set("Vary", "Accept-Encoding")
 	g.Header().Del("Content-Length")
 	g.ResponseWriter.WriteHeader(code)
 }
+
+func (g *gzipWriter) isGzipped(input []byte) bool {
+	if len(input) < 2 {
+		return false
+	}
+	return input[0] == 0x1f && input[1] == 0x8b
+}
diff --git a/handler.go b/handler.go
index 7de33eb..0144228 100644
--- a/handler.go
+++ b/handler.go
@@ -52,7 +52,7 @@ func (g *gzipHandler) Handle(c *gin.Context) {
 
 	c.Header("Content-Encoding", "gzip")
 	c.Header("Vary", "Accept-Encoding")
-	c.Writer = &gzipWriter{c.Writer, gz}
+	c.Writer = &gzipWriter{c.Writer, gz, false}
 	defer func() {
 		gz.Close()
 		c.Header("Content-Length", fmt.Sprint(c.Writer.Size()))