diff --git a/rtc_tools/metrics_plotter.py b/rtc_tools/metrics_plotter.py
index 3b746ad8ee..804bc8fd71 100644
--- a/rtc_tools/metrics_plotter.py
+++ b/rtc_tools/metrics_plotter.py
@@ -88,7 +88,8 @@ def main():
         plt.ylabel('%s (%s)' % (metric[GRAPH_NAME], metric[UNITS]))
         plt.xlabel('time (s)')
         plt.title(metric[GRAPH_NAME])
-        plt.plot(x_values, y_values)
+        plt.plot(x_values, y_values, marker='x', markersize=3,
+                 markeredgecolor='red')
 
     plt.show()