diff --git a/download.sh b/download.sh
index 7957b8285f196550069e926609644465d2980d99..ce817bdf2c57ff7760161673efc2ed31a917584d 100755
--- a/download.sh
+++ b/download.sh
@@ -21,10 +21,10 @@ mkdir -p bin
 CHECKOUTBRANCH=""
 setCheckoutBranch() {
   CHECKOUTBRANCH="release"
-  if [ -z "$FBRANCH"]; then
+  if [[ -z "$FBRANCH" ]]; then
     CHECKOUTBRANCH=$FBRANCH
   fi
-  if [ -z "$FBRANCH2"]; then
+  if [[ -z "$FBRANCH2" ]]; then
     CHECKOUTBRANCH=$FBRANCH2
   fi