diff --git a/undo.bat b/undo.bat
index efc9fa8..4067b04 100644
--- a/undo.bat
+++ b/undo.bat
@@ -12,8 +12,8 @@ exit
 :start
 for /F "skip=3 tokens=1,2,3* delims= " %%G in ('netsh interface show interface') DO (
     IF "%%H"=="Connected" netsh interface ip set address "%%J" dhcp
-) >NUL
+) >nul
 
 for /F "skip=3 tokens=1,2,3* delims= " %%G in ('netsh interface show interface') DO (
     IF "%%H"=="Connected" netsh interface ip set dns "%%J" dhcp
-) >NUL
+) >nul