diff --git a/build-aux/git-version-gen b/build-aux/git-version-gen
index b08432468fbb26f24364b3e557e9506893e48a47..0ea1638a025aaba6bfe93500dc88785fcf388b97 100755
--- a/build-aux/git-version-gen
+++ b/build-aux/git-version-gen
@@ -8,7 +8,7 @@ elif test -s version; then
   VN=`cat version`
 elif test -e .git; then
  VN="0.0.0-`git rev-list --count HEAD`+`git describe --always`"
- git update-index -q --refresh
+ git update-index -q --refresh >/dev/null 2>&1
  test x = x"`git diff-index --name-only HEAD --`" || VN="${VN}-dirty"
 else
   echo "Cannot determine version number">&2