diff --git a/Makefile b/Makefile
index 6eb32a5..05faa5c 100644
--- a/Makefile
+++ b/Makefile
@@ -1,18 +1,18 @@
 NAME=tun2socks
-BUILDDIR=$(shell pwd)/build
-CMDDIR=$(shell pwd)/cmd
+BUILD_DIR=$(shell pwd)/build
+CMD_DIR=$(shell pwd)/cmd
 VERSION=$(shell git describe --tags --long || echo "unknown version")
+BUILD_TIME=$(shell date -u)
 BUILD_TAGS='fakeDNS stats'
-BUILD_LDFLAGS='-s -w -X "main.version=$(VERSION)"'
-DEBUG_BUILD_LDFLAGS='-s -w -X "main.version=$(VERSION)-debug"'
+BUILD_LDFLAGS='-s -w -X "github.com/xjasonlyu/tun2socks/constant.Version=$(VERSION)" -X "github.com/xjasonlyu/tun2socks/constant.BuildTime=$(BUILD_TIME)"'
 
 all: build
 
 build:
-	cd $(CMDDIR) && go build -ldflags $(BUILD_LDFLAGS) -v -tags $(BUILD_TAGS) -o $(BUILDDIR)/$(NAME)
+	cd $(CMD_DIR) && go build -ldflags $(BUILD_LDFLAGS) -v -tags $(BUILD_TAGS) -o $(BUILD_DIR)/$(NAME)
 
 debug:
-	cd $(CMDDIR) && go build -ldflags $(DEBUG_BUILD_LDFLAGS) -v -tags $(BUILD_TAGS) -race -o $(BUILDDIR)/$(NAME)
+	cd $(CMD_DIR) && go build -ldflags $(BUILD_LDFLAGS) -v -tags $(BUILD_TAGS) -race -o $(BUILD_DIR)/$(NAME)
 
 clean:
-	rm -rf $(BUILDDIR)
\ No newline at end of file
+	rm -rf $(BUILD_DIR)
\ No newline at end of file
diff --git a/cmd/main.go b/cmd/main.go
index 6e9b0c5..2e23e15 100644
--- a/cmd/main.go
+++ b/cmd/main.go
@@ -19,6 +19,7 @@ import (
 
 	D "github.com/xjasonlyu/tun2socks/common/dns"
 	S "github.com/xjasonlyu/tun2socks/common/stats"
+	C "github.com/xjasonlyu/tun2socks/constant"
 
 	// init logger
 	_ "github.com/xjasonlyu/tun2socks/common/log/simple"
@@ -27,9 +28,6 @@ import (
 const MTU = 1500
 
 var (
-	version     = "unknown version"
-	description = "A tun2socks implementation written in Go."
-
 	args            = new(CmdArgs)
 	postFlagsInitFn []func()
 
@@ -87,8 +85,7 @@ func main() {
 	flag.Parse()
 
 	if *args.Version {
-		fmt.Println("Go-tun2socks", version)
-		fmt.Println(description)
+		fmt.Println("Go-tun2socks", C.Version, C.BuildTime)
 		os.Exit(0)
 	}
 
diff --git a/constant/version.go b/constant/version.go
new file mode 100644
index 0000000..17a26f8
--- /dev/null
+++ b/constant/version.go
@@ -0,0 +1,6 @@
+package constant
+
+var (
+	Version   = "unknown version"
+	BuildTime = "unknown time"
+)