1 files changed, 2 insertions, 2 deletions
diff --git a/src/grossmeister/move_selector.rs b/src/grossmeister/move_selector.rs
index 3ca2f1a..d26ffc0 100644
--- a/src/grossmeister/move_selector.rs
+++ b/src/grossmeister/move_selector.rs
@@ -74,7 +74,7 @@ impl MoveGenStage {
 pub struct MoveSelector {
     all_moves: ScoredMoveList,
     stage_moves: ScoredMoveIter,
-    pub killer_moves: MoveList,
+    pub killer_moves: SmallVec<[Move; 4]>,
     stage: MoveGenStage,
 }
 
@@ -98,8 +98,8 @@ impl Grossmeister {
             let parent_killers = &mut self.move_selectors[(self.board.ply - 2) as usize].killer_moves;
             match parent_killers.iter().find(|m| **m == killer) {
                 None => {
-                    // println!("Registering killer {:?} for ply {}", killer, self.board.ply - 1);
                     parent_killers.push(killer);
+                    debug_assert!(!parent_killers.spilled(), "Killer move list should remain on the stack");
                     // We want to have max 3 killers, so if we exceed the limit remove the oldest killer
                     if parent_killers.len() > 3 {
                         parent_killers.remove(0);