diff --git a/selfdrive/ui/qt/onroad.cc b/selfdrive/ui/qt/onroad.cc
index 7e83833..73b34e9 100755
--- a/selfdrive/ui/qt/onroad.cc
+++ b/selfdrive/ui/qt/onroad.cc
@@ -441,7 +441,7 @@ void AnnotatedCameraWidget::drawHud(QPainter &p) {
   p.restore();
 
   if (!scene.hide_max_speed) {
-    drawSpeedWidget (p, 60, 45, QString("MAX"), QString("33"), QColor(0xff, 0xff, 0xff));
+    drawSpeedWidget (p, 60, 45, const QString("MAX"), const QString("33"), const QColor(0xff, 0xff, 0xff));
   }
 
   // Draw FrogPilot widgets
@@ -504,7 +504,7 @@ void AnnotatedCameraWidget::drawHud(QPainter &p) {
 //   }
 // }
 
-void AnnotatedCameraWidget::drawSpeedWidget(QPainter &p, int &x, int &y, QString &title, QString &speedLimitStr, QColor &colorSpeed) {
+void AnnotatedCameraWidget::drawSpeedWidget(QPainter &p, int &x, int &y, const QString &title, const QString &speedLimitStr, QColor &colorSpeed) {
     // Draw outer box + border to contain set speed and speed limit
     const int sign_margin = 12;
     const int us_sign_height = 186;
diff --git a/selfdrive/ui/qt/onroad.h b/selfdrive/ui/qt/onroad.h
index 468df60..92de24d 100755
--- a/selfdrive/ui/qt/onroad.h
+++ b/selfdrive/ui/qt/onroad.h
@@ -97,7 +97,7 @@ public:
 
 private:
   void drawText(QPainter &p, int x, int y, const QString &text, int alpha = 255);
-  void drawSpeedWidget(QPainter &p, int x, int y, QString &title, QString &speedLimitStr, QColor &colorSpeed);
+  void drawSpeedWidget(QPainter &p, int &x, int &y, const QString &title, const QString &speedLimitStr, QColor &colorSpeed);
 
   QVBoxLayout *main_layout;
   QPixmap dm_img;