diff --git a/msupdate.ps1 b/msupdate.ps1
index 8169973..df9097b 100644
--- a/msupdate.ps1
+++ b/msupdate.ps1
@@ -60,7 +60,7 @@ $isomount = (Mount-DiskImage -ImagePath $isopath -PassThru | Get-Volume).DriveLe
 
 # write W10UI conf
 "[W10UI-Configuration]
-Target        =$isomount
+Target        =${isomount}:
 Repo          =%cd%\patch
 DismRoot      =dism.exe