diff --git a/examples/trader-runner-selenium/jetty-server.sh b/examples/trader-runner-selenium/jetty-server.sh
index 09af14a..6f30ed3 100755
--- a/examples/trader-runner-selenium/jetty-server.sh
+++ b/examples/trader-runner-selenium/jetty-server.sh
@@ -10,7 +10,7 @@ start()
 # ----- Execute the commands -----------------------------------------
 
 MODULE=$1
-if [ "$MODULE" == "" ]; then
+if test -z "$MODULE"; then
 MODULE="../trader-runner"
 fi
 
diff --git a/examples/trader-runner-selenium/selenium-server.sh b/examples/trader-runner-selenium/selenium-server.sh
index d75a229..9ec9003 100755
--- a/examples/trader-runner-selenium/selenium-server.sh
+++ b/examples/trader-runner-selenium/selenium-server.sh
@@ -10,10 +10,10 @@ start()
 
 M2_REPOSITORY=$1
 VERSION=$2
-if [ "$M2_REPOSITORY" == "" ]; then
+if test -z "$MODULE"; then
 M2_REPOSITORY="$HOME/.m2/repository"
 fi
-if [ "$VERSION" == "" ]; then
+if test -z "$VERSION"; then
 VERSION="1.0.2"
 fi