diff --git a/oscar/update_gitinfo.bat b/oscar/update_gitinfo.bat
index e19b0baf..756f7590 100755
--- a/oscar/update_gitinfo.bat
+++ b/oscar/update_gitinfo.bat
@@ -9,8 +9,8 @@ if "%GIT_DIR%"=="" goto GitDone
 for /f %%i in ('git rev-parse --abbrev-ref HEAD') do set GIT_BRANCH=%%i
 if "%GIT_BRANCH%"=="HEAD" set GIT_BRANCH=""
 for /f %%i in ('git rev-parse --short HEAD') do set GIT_REVISION=%%i
-for /f %%i in ('git diff-index --quiet HEAD --') do set GIT_INDEX=%%i
-if "%GIT_INDEX%"!=="" (
+git diff-index --quiet HEAD --
+if %ERRORLEVEL% NEQ 0 (
   set GIT_REVISION=%GIT_REVISION%-plus
   set GIT_TAG=
   goto GitDone