diff --git a/internal/server/server.go b/internal/server/server.go
index 525992e..6008fad 100644
--- a/internal/server/server.go
+++ b/internal/server/server.go
@@ -7,7 +7,7 @@ import (
 	"github.com/gin-gonic/gin"
 )
 
-func Launch(port int, indent int, char string, fn func(s string, indent int, char string) (string, error)) {
+func Launch(port int, indent int, char string, fn func(s string, indent int, char string) (string, error)) error {
 	gin.SetMode(gin.ReleaseMode)
 
 	router := gin.Default()
@@ -29,5 +29,5 @@ func Launch(port int, indent int, char string, fn func(s string, indent int, cha
 		c.Data(http.StatusOK, "text/javascript", CACHE_SCRIPT)
 	})
 
-	router.Run(fmt.Sprintf(":%d", port))
+	return router.Run(fmt.Sprintf(":%d", port))
 }
diff --git a/main.go b/main.go
index f9f321b..78580dd 100644
--- a/main.go
+++ b/main.go
@@ -16,7 +16,10 @@ func main() {
 
 	src, dest, indent, char, web, port := cmd.InitArgv()
 	if web {
-		server.Launch(port, indent, char, formatter.Formatter)
+		err := server.Launch(port, indent, char, formatter.Formatter)
+		if err != nil {
+			log.Fatal(err)
+		}
 	} else {
 		err := updater.UpdateConfInDir(src, dest, indent, char, formatter.Formatter)
 		if err != nil {