diff --git a/glog_file.go b/glog_file.go
index 053c203..1bcfaaa 100644
--- a/glog_file.go
+++ b/glog_file.go
@@ -25,6 +25,7 @@
 	"os"
 	"os/user"
 	"path"
+	"path/filepath"
 	"strings"
 	"sync"
 	"time"
@@ -55,7 +56,7 @@
 		if len(dir) == 0 {
 			continue
 		}
-		if dir[0] != '/' {
+		if !filepath.IsAbs(dir) {
 			dir = "/" + dir
 		}
 		logDirs = append(logDirs, dir)