diff --git a/src/trekstor.rs b/src/trekstor.rs
index 15481b9..44887b8 100644
--- a/src/trekstor.rs
+++ b/src/trekstor.rs
@@ -36,15 +36,12 @@ impl Trekstor {
     }
 
     pub fn update(&mut self, update: UpdateFn) {
-        let mut last_frame_time = Instant::now();
         loop {
             self.input.handle_event();
             self.current_time = Instant::now();
+            let dt = self.current_time - self.last_time;
 
-            println!(
-                "FPS: {}",
-                (self.current_time - last_frame_time).as_secs_f64()
-            );
+            println!("FPS: {}", dt.as_millis());
 
             if !update(&mut self.screen, &self.input) {
                 return;
@@ -53,9 +50,7 @@ impl Trekstor {
             self.screen.flush();
             self.input.finish();
 
-            let dt = self.current_time - self.last_time;
             self.last_time = self.current_time;
-            last_frame_time = Instant::now();
             if dt < self.update_timestep {
                 sleep(self.update_timestep - dt);
             }