diff --git a/fuzzers/FRET/src/clock.rs b/fuzzers/FRET/src/clock.rs
index adc3e597c3..a63b9a36b5 100644
--- a/fuzzers/FRET/src/clock.rs
+++ b/fuzzers/FRET/src/clock.rs
@@ -84,7 +84,7 @@ impl Default for MaxIcountMetadata {
 
 /// A piece of metadata tracking all icounts
 #[derive(Debug, SerdeAny, Serialize, Deserialize)]
-pub struct IcHist(pub Vec<u64>);
+pub struct IcHist (pub Vec<u64>, pub u64);
 
 //========== Observer
 
@@ -139,10 +139,11 @@ where
         let hist = metadata.get_mut::<IcHist>();
         match hist {
             None => {
-                metadata.insert(IcHist(vec![self.end_tick - self.start_tick]));
+                metadata.insert(IcHist(vec![self.end_tick - self.start_tick], self.end_tick-self.start_tick));
             }
             Some(v) => {
                 v.0.push(self.end_tick - self.start_tick);
+                v.1 = max(v.1, self.end_tick - self.start_tick);
                 if v.0.len() >= 100 {
                     if let Ok(td) = env::var("TIME_DUMP") {
                         let mut file = OpenOptions::new()
diff --git a/fuzzers/FRET/src/mutational.rs b/fuzzers/FRET/src/mutational.rs
index dda8d4a36f..eabe1540f2 100644
--- a/fuzzers/FRET/src/mutational.rs
+++ b/fuzzers/FRET/src/mutational.rs
@@ -351,7 +351,10 @@ where
             }
             #[cfg(not(feature = "feed_systemtrace"))]
             {
-                let maxtick : u64 = (_input.exec_time().expect("No duration found").as_nanos() >> 4).try_into().unwrap();
+                let metadata = state.metadata();
+                let hist = metadata.get::<IcHist>().unwrap();
+                let maxtick : u64 = hist.1;
+                // let maxtick : u64 = (_input.exec_time().expect("No duration found").as_nanos() >> 4).try_into().unwrap();
                 let mut numbers : Vec<u32> = vec![];
                 for i in 0..num_interrupts {
                     prefix.push(u32::to_le_bytes(myrand.between(0, maxtick).try_into().unwrap()));