diff --git a/weed/glog/glog_file.go b/weed/glog/glog_file.go
index 65075d281..bb8e6902f 100644
--- a/weed/glog/glog_file.go
+++ b/weed/glog/glog_file.go
@@ -38,7 +38,7 @@ var logDirs []string
 
 // If non-empty, overrides the choice of directory in which to write logs.
 // See createLogDirs for the full list of possible destinations.
-var logDir = flag.String("log_dir", "", "If non-empty, write log files in this directory")
+var logDir = flag.String("logdir", "", "If non-empty, write log files in this directory")
 
 func createLogDirs() {
 	if *logDir != "" {