diff --git a/satrs-minisim/src/controller.rs b/satrs-minisim/src/controller.rs
index d725e45..ba0fe78 100644
--- a/satrs-minisim/src/controller.rs
+++ b/satrs-minisim/src/controller.rs
@@ -49,18 +49,18 @@ impl SimController {
     }
 
     pub fn run(&mut self, start_time: MonotonicTime, udp_polling_interval_ms: u64) {
-        let mut t = start_time + Duration::from_millis(udp_polling_interval_ms);
-        self.sys_clock.synchronize(t);
+        let mut t = start_time;
         loop {
+            let t_old = t;
             // Check for UDP requests every millisecond. Shift the simulator ahead here to prevent
             // replies lying in the past.
             t += Duration::from_millis(udp_polling_interval_ms);
+            self.sys_clock.synchronize(t);
+            self.handle_sim_requests();
             self.simulation
                 .step_until(t)
                 .expect("simulation step failed");
-            self.handle_sim_requests();
 
-            self.sys_clock.synchronize(t);
         }
     }
 
diff --git a/satrs-minisim/src/lib.rs b/satrs-minisim/src/lib.rs
index 215e5d4..23148b7 100644
--- a/satrs-minisim/src/lib.rs
+++ b/satrs-minisim/src/lib.rs
@@ -1,3 +1,4 @@
+use asynchronix::time::MonotonicTime;
 use serde::{de::DeserializeOwned, Deserialize, Serialize};
 
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Serialize, Deserialize)]
@@ -19,6 +20,7 @@ pub struct SimMessage {
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
 pub struct SimRequest {
     inner: SimMessage,
+    timestamp: MonotonicTime
 }
 
 #[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]