diff --git a/crates/domain/src/scheduler/multi_core.rs b/crates/domain/src/scheduler/multi_core.rs
index 3174ac4..3ddfcff 100644
--- a/crates/domain/src/scheduler/multi_core.rs
+++ b/crates/domain/src/scheduler/multi_core.rs
@@ -37,18 +37,16 @@ impl MultiCoreScheduler {
             .count()
     }
 
-    fn least_loaded_core(&self) -> CoreId {
+    fn least_loaded_core(&self) -> Option<CoreId> {
         (0..self.num_cores)
             .map(|i| CoreId::from_raw(i))
             .min_by_key(|&c| self.thread_count_on(c))
-            .unwrap()
     }
 
-    fn most_loaded_core(&self) -> CoreId {
+    fn most_loaded_core(&self) -> Option<CoreId> {
         (0..self.num_cores)
             .map(|i| CoreId::from_raw(i))
             .max_by_key(|&c| self.thread_count_on(c))
-            .unwrap()
     }
 }
 
@@ -77,9 +75,10 @@ impl Scheduler for MultiCoreScheduler {
             let core_idx = core.raw() as usize;
             if let Some(highest) = self.cores[core_idx].highest_waiting_priority() {
                 if highest > current_priority {
-                    let next = self.cores[core_idx].pick_next().unwrap();
-                    self.cores[core_idx].add(current, current_priority);
-                    return SchedulerDecision::Preempt(next);
+                    if let Some(next) = self.cores[core_idx].pick_next() {
+                        self.cores[core_idx].add(current, current_priority);
+                        return SchedulerDecision::Preempt(next);
+                    }
                 }
             }
         }
@@ -87,8 +86,10 @@ impl Scheduler for MultiCoreScheduler {
     }
 
     fn balance(&mut self) {
-        let busiest = self.most_loaded_core();
-        let lightest = self.least_loaded_core();
+        let (busiest, lightest) = match (self.most_loaded_core(), self.least_loaded_core()) {
+            (Some(b), Some(l)) => (b, l),
+            _ => return,
+        };
 
         if self.thread_count_on(busiest) > self.thread_count_on(lightest) + BALANCE_THRESHOLD {
             let busiest_idx = busiest.raw() as usize;
diff --git a/crates/domain/src/scheduler/priority_queue.rs b/crates/domain/src/scheduler/priority_queue.rs
index 9d5dc13..f9c345a 100644
--- a/crates/domain/src/scheduler/priority_queue.rs
+++ b/crates/domain/src/scheduler/priority_queue.rs
@@ -99,7 +99,7 @@ impl PriorityQueue {
         if self.queues[idx].is_empty() {
             self.bitmap &= !(1 << idx);
         }
-        Some((thread, Priority::new(idx as u8).unwrap()))
+        Some((thread, Priority::new(idx as u8)?))
     }
 
     pub fn highest_priority(&self) -> Option<Priority> {
@@ -107,7 +107,7 @@ impl PriorityQueue {
             return None;
         }
         let idx = 31 - self.bitmap.leading_zeros() as usize;
-        Some(Priority::new(idx as u8).unwrap())
+        Priority::new(idx as u8)
     }
 
     pub fn steal_lowest(&mut self) -> Option<(ThreadId, Priority)> {
@@ -119,7 +119,7 @@ impl PriorityQueue {
         if self.queues[idx].is_empty() {
             self.bitmap &= !(1 << idx);
         }
-        Some((thread, Priority::new(idx as u8).unwrap()))
+        Some((thread, Priority::new(idx as u8)?))
     }
 
     pub fn is_empty(&self) -> bool {