diff --git a/learning_ompl/install-ompl-ubuntu.sh b/learning_ompl/install-ompl-ubuntu.sh
index 733ffcf..9df73d5 100755
--- a/learning_ompl/install-ompl-ubuntu.sh
+++ b/learning_ompl/install-ompl-ubuntu.sh
@@ -3,7 +3,7 @@
 set -e
 
 if [ `id -u` == 0 ]; then
-    SUDO=''
+    SUDO=
     export DEBIAN_FRONTEND=noninteractive
     apt-get -y install lsb-release
 else