diff --git a/rawhammer/src/main.rs b/rawhammer/src/main.rs
index 463b2bc..cb2ba5e 100644
--- a/rawhammer/src/main.rs
+++ b/rawhammer/src/main.rs
@@ -187,16 +187,21 @@ static CH_NTRU: &'static [u8] = b"\
 \x00\x2d\x00\x02\x01\x01\x00\x2b\x00\x09\x08\x03\x04\x03\x03\x03\
 \x02\x03\x01";
 
-fn sleep(micros: u64, cmt: &'static str) {
+fn sleep(micros: u128, cmt: &'static str) {
     println!("[START] {}", cmt);
     sleep_no_comment(micros);
     println!("[DONE] {}", cmt);
 }
 
-fn sleep_no_comment(micros: u64) {
+fn sleep_no_comment(micros: u128) {
     if micros > 0 {
-        let dur_micros = time::Duration::from_micros(micros);
-        thread::sleep(dur_micros);
+        if micros > 1000 {
+            let dur_micros = time::Duration::from_micros(micros as u64);
+            thread::sleep(dur_micros);
+        } else {
+            let t1 = Instant::now();
+            while t1.elapsed().as_micros() < micros {}
+        }
     }
 }
 
@@ -258,6 +263,8 @@ fn main() -> std::io::Result<()> {
     let mut threads = Vec::new();
     // report every 1000 msgs sent
     let msg_nb_report = 1000;
+    // sleep time in microseconds between each message
+    let usleep = 1000000/msg_per_sec as u128;
     for _ in 0..sending_threads {
         // Condition variables to control threads
         let t = thread::spawn(move || {
@@ -280,7 +287,7 @@ fn main() -> std::io::Result<()> {
                     _ => panic!("Unknown case"),
                 };
                 s.shutdown(Shutdown::Both).expect("shutdown call failed");
-                sleep_no_comment(1000000/msg_per_sec as u64);
+                sleep_no_comment(usleep);
                 ch_sent += 1;
                 if ch_sent % msg_nb_report == 0 {
                     println!("nb of queries sent: total: {}. {1} msg's in {2} sec. {3} per sec",