diff --git a/OSBindings/Qt/mainwindow.cpp b/OSBindings/Qt/mainwindow.cpp
index f4bf5eeb8..1bb23dffd 100644
--- a/OSBindings/Qt/mainwindow.cpp
+++ b/OSBindings/Qt/mainwindow.cpp
@@ -715,6 +715,8 @@ void MainWindow::setUIPhase(UIPhase phase) {
 	// widgets aren't still selectable after a machine starts.
 	if(phase != UIPhase::SelectingMachine) {
 		ui->openGLWidget->setFocus();
+	} else {
+		ui->startMachineButton->setDefault(true);
 	}
 
 	// Indicate whether to catch mouse input.
diff --git a/OSBindings/Qt/scantargetwidget.cpp b/OSBindings/Qt/scantargetwidget.cpp
index 00f11e492..99072b486 100644
--- a/OSBindings/Qt/scantargetwidget.cpp
+++ b/OSBindings/Qt/scantargetwidget.cpp
@@ -143,13 +143,20 @@ void ScanTargetWidget::setMouseDelegate(MouseDelegate *delegate) {
 }
 
 void ScanTargetWidget::keyPressEvent(QKeyEvent *event) {
+	// Use CTRL+Escape to end mouse captured mode, if currently captured; otherwise ignore the event.
+	// Empirical note: control actually appears to mean command on the Mac. I have no idea what the
+	// Mac's command key would actually be as a modifier. Fingers crossed control means control
+	// elsewhere (?).
 	if(mouseIsCaptured && event->key() == Qt::Key_Escape && event->modifiers()&Qt::ControlModifier) {
 		releaseMouse();
 
 		QCursor cursor;
 		cursor.setShape(Qt::ArrowCursor);
 		setCursor(cursor);
+		return;
 	}
+
+	event->ignore();
 }
 
 void ScanTargetWidget::releaseMouse() {