diff --git a/script/build/test_startup.sh b/script/build/test_startup.sh
index 685d101ef..970d2f69b 100755
--- a/script/build/test_startup.sh
+++ b/script/build/test_startup.sh
@@ -4,7 +4,7 @@ APP_PORT=$2
 WS_PORT=$3
 
 rails r "Setting.set('developer_mode', true)"
-rails r "Setting.set('websocket_port', '#{WS_PORT}')"
+rails r "Setting.set('websocket_port', '$WS_PORT')"
 
 pumactl start --pidfile tmp/pids/puma.pid -d -p $APP_PORT -e $RAILS_ENV
 script/websocket-server.rb start -d -p $WS_PORT