diff --git a/run.sh b/run.sh
index 32033f0..26ea270 100755
--- a/run.sh
+++ b/run.sh
@@ -35,7 +35,7 @@ cd $(dirname "$0") || error "Failure to change direcory!"
 $PYTHON -c "import pip" || error "Please install pip first!"
 $PYTHON -c "import easy_install" || error "Please install setuptools first!"
 
-if [ ! -d $TOOLS_DIR ]; then
+if [ ! -d "$TOOLS_DIR" ]; then
   error "$TOOLS_DIR directory not exists"
 fi