diff --git a/build/branch.sh b/build/branch.sh
index 023a3f192ad9e366d03809e91e524dd5407daaca..b64681ff13686d08d2a62bc731ef653e2b665cf7 100755
--- a/build/branch.sh
+++ b/build/branch.sh
@@ -31,7 +31,7 @@ case $child in
   *) child="b_$child"
 esac
 
-if test "$parent" != "HEAD" && test -f $dir/CVS/Tag && "`cat $dir/CVS/Tag`" != "T$parent"; then
+if test "$parent" != "HEAD" -a -f $dir/CVS/Tag -a "`cat $dir/CVS/Tag`" != "T$parent"; then
 	echo "This script must be run within the $parent branch"
 	exit 1
 fi