diff --git a/trunk/scripts/csdn.mirror.sh b/trunk/scripts/csdn.mirror.sh
index bd5a852c2..7dc357faa 100755
--- a/trunk/scripts/csdn.mirror.sh
+++ b/trunk/scripts/csdn.mirror.sh
@@ -14,7 +14,7 @@ work_dir=`(cd ${work_dir}/.. && pwd)`
 product_dir=$work_dir
 
 # allow start script from any dir
-cd $work_dir
+cd $work_dir && git checkout master
 
 . ${product_dir}/scripts/_log.sh
 ret=$?; if [[ $ret -ne 0 ]]; then exit $ret; fi
diff --git a/trunk/scripts/oschina.mirror.sh b/trunk/scripts/oschina.mirror.sh
index e47e172aa..47841b529 100755
--- a/trunk/scripts/oschina.mirror.sh
+++ b/trunk/scripts/oschina.mirror.sh
@@ -14,7 +14,7 @@ work_dir=`(cd ${work_dir}/.. && pwd)`
 product_dir=$work_dir
 
 # allow start script from any dir
-cd $work_dir
+cd $work_dir && git checkout master
 
 . ${product_dir}/scripts/_log.sh
 ret=$?; if [[ $ret -ne 0 ]]; then exit $ret; fi