diff --git a/weed/command/volume.go b/weed/command/volume.go
index d0fdd2ed1..ba8c1a550 100644
--- a/weed/command/volume.go
+++ b/weed/command/volume.go
@@ -92,7 +92,7 @@ var (
 	volumeFolders         = cmdVolume.Flag.String("dir", os.TempDir(), "directories to store data files. dir[,dir]...")
 	maxVolumeCounts       = cmdVolume.Flag.String("max", "7", "maximum numbers of volumes, count[,count]... If set to zero on non-windows OS, the limit will be auto configured.")
 	volumeWhiteListOption = cmdVolume.Flag.String("whiteList", "", "comma separated Ip addresses having write permission. No limit if empty.")
-	minFreeSpacePercent   = cmdVolume.Flag.String("minFreeSpacePercent ", "0", "minimum free disk space(in percents). If free disk space lower this value - all volumes marks as ReadOnly")
+	minFreeSpacePercent   = cmdVolume.Flag.String("minFreeSpacePercent", "0", "minimum free disk space(in percents). If free disk space lower this value - all volumes marks as ReadOnly")
 )
 
 func runVolume(cmd *Command, args []string) bool {