diff --git a/src/lephisto.c b/src/lephisto.c
index 5157ee0..fc1df01 100644
--- a/src/lephisto.c
+++ b/src/lephisto.c
@@ -559,7 +559,8 @@ static double fps_cur = 0.; /**< FPS accumulator to trigger change. */
  */
 static void display_fps(const double dt) {
   double x, y;
-  fps_dt += dt;
+
+  fps_dt += dt / dt_mod;
   fps_cur += 1.;
   if(fps_dt > 1.) {
     /* Recalculate every second. */