diff --git a/build.sh b/build.sh
index ce6eb54..9c2e552 100755
--- a/build.sh
+++ b/build.sh
@@ -130,6 +130,6 @@ cd $SH_PATH
 
 dockerbuild
 
-if [ ! -n $SKIP_UPLOAD ];then
+if [ ! -n "$SKIP_UPLOAD" ];then
 	upload_pkg || errlog "upload pkg failed"
 fi