diff --git a/client/main.cpp b/client/main.cpp
index ea7b050..9488e5f 100644
--- a/client/main.cpp
+++ b/client/main.cpp
@@ -28,17 +28,23 @@ int main(int argc, char *argv[])
     parser.setApplicationDescription("unisim_cpp client");
     parser.addHelpOption();
 
-    QCommandLineOption hostOption(QStringList() << "s"
-                                                << "server",
-                                  QCoreApplication::translate("main", "sim-us server host [default: localhost]."),
-                                  QCoreApplication::translate("main", "host"), QLatin1String("localhost"));
-    parser.addOption(hostOption);
+    QCommandLineOption host_option(QStringList() << "s"
+                                                 << "server",
+                                   QCoreApplication::translate("main", "unisim_cpp server host [default: localhost]."),
+                                   QCoreApplication::translate("main", "host"), QLatin1String("localhost"));
+    parser.addOption(host_option);
 
-    QCommandLineOption portOption(QStringList() << "p"
-                                                << "port",
-                                  QCoreApplication::translate("main", "Port for echoserver [default: 9002]."),
-                                  QCoreApplication::translate("main", "port"), QLatin1String("9002"));
-    parser.addOption(portOption);
+    QCommandLineOption port_option(QStringList() << "p"
+                                                 << "port",
+                                   QCoreApplication::translate("main", "Port for unisim_cpp [default: 9002]."),
+                                   QCoreApplication::translate("main", "port"), QLatin1String("9002"));
+    parser.addOption(port_option);
+
+    QCommandLineOption default_sim_option(QStringList() << "d"
+                                                        << "default",
+                                          QCoreApplication::translate("main", "Default sim that loads on startup."),
+                                          QCoreApplication::translate("main", "default"), QLatin1String(""));
+    parser.addOption(default_sim_option);
 
     parser.process(a);
     // Initialize the logger
@@ -46,9 +52,10 @@ int main(int argc, char *argv[])
 
     QUrl url;
     url.setScheme("ws");
-    url.setHost(parser.value(hostOption));
-    url.setPort(parser.value(portOption).toInt());
-    MainWindow w(url);
+    url.setHost(parser.value(host_option));
+    url.setPort(parser.value(port_option).toInt());
+    QString default_sim = parser.value(default_sim_option);
+    MainWindow w(url, default_sim);
     w.show();
     return a.exec();
 }
diff --git a/client/mainwindow.cpp b/client/mainwindow.cpp
index 0fd6542..0305ff1 100644
--- a/client/mainwindow.cpp
+++ b/client/mainwindow.cpp
@@ -7,7 +7,7 @@
 
 typedef Simulator_base *(*Get_UI)(Web_socket_wrapper *, QWidget *);
 
-MainWindow::MainWindow(QUrl ws_url, QWidget *parent)
+MainWindow::MainWindow(QUrl ws_url, QString sim, QWidget *parent)
     : QMainWindow(parent), ui(new Ui::MainWindow), m_web_socket(new Web_socket_wrapper(ws_url)),
       m_error_dialog(new NetworkError(this))
 {
@@ -36,7 +36,8 @@ MainWindow::MainWindow(QUrl ws_url, QWidget *parent)
     m_error_dialog->set_error("Connection timed out\nCheck if the server is running");
     ui->connection->setText("Connected to " + ws_url.toString());
     // Default sim
-    // defaultSim("CVS_I10");
+    if (!sim.isEmpty())
+        default_sim(sim);
 
     connect(ui->pushButton, &QPushButton::clicked, this, [=, this] { open_sim(ui->comboBox->currentText()); });
     connect(this, &MainWindow::quit, this, &QCoreApplication::quit, Qt::QueuedConnection);
@@ -70,7 +71,7 @@ void MainWindow::hideEvent(QHideEvent *event)
     disconnect(m_web_socket.get(), nullptr, nullptr, nullptr);
 }
 
-void MainWindow::defaultSim(QString name)
+void MainWindow::default_sim(QString name)
 {
     this->m_selected_sim_name = name;
     this->m_default_sim = true;
diff --git a/client/mainwindow.hpp b/client/mainwindow.hpp
index 08f1810..00589a9 100644
--- a/client/mainwindow.hpp
+++ b/client/mainwindow.hpp
@@ -20,10 +20,10 @@ class MainWindow : public QMainWindow
     Q_OBJECT
 
   public:
-    explicit MainWindow(QUrl ws_url, QWidget *parent = nullptr);
+    explicit MainWindow(QUrl ws_url, QString sim, QWidget *parent = nullptr);
     ~MainWindow();
 
-    void defaultSim(QString name);
+    void default_sim(QString name);
     void pase_sim_names(json &sims);
     void open_sim_window(void);
     void check_active_sim(QString name);