diff --git a/services/scripts/run_server_image.sh b/services/scripts/run_server_image.sh
index cf8dbf6e5..1b836b6ab 100755
--- a/services/scripts/run_server_image.sh
+++ b/services/scripts/run_server_image.sh
@@ -1,33 +1,33 @@
 #!/usr/bin/env bash
 
 set -e
 
 if [ "$#" -lt 1 ] || [ "$#" -gt 2 ]; then
-  echo "Illegal number of parameters, expected:"
+  echo "Illegal number of arguments, expected 2:"
   echo "- one argument with a name of the service, currently available services:"
   ./scripts/list_services.sh
   echo "- one optional argument with port"
   echo "- example: ./services/scripts/run_server_image.sh tunnelbroker 12345"
   exit 1;
 fi
 
 SERVICE=$1
 if [ "$SERVICE" == "tunnelbroker" ]; then
-  if [ ! -z "$2" ]; then
+  if [ -n "$2" ]; then
     export COMM_SERVICES_PORT_TUNNELBROKER=$2
   fi
 elif [ "$SERVICE" == "backup" ]; then
-  if [ ! -z "$2" ]; then
+  if [ -n "$2" ]; then
     export COMM_SERVICES_PORT_BACKUP=$2
   fi
 elif [ "$SERVICE" == "blob" ]; then
-  if [ ! -z "$2" ]; then
+  if [ -n "$2" ]; then
     export COMM_SERVICES_PORT_BLOB=$2
   fi
 else
   echo "No such service ${SERVICE}, aborting"
   exit 1
 fi
 
-docker-compose build $SERVICE-server
-docker-compose up $SERVICE-server
+docker-compose build "$SERVICE"-server
+docker-compose up "$SERVICE"-server