diff --git a/arithmetization/src/main/java/net/consensys/linea/zktracer/container/stacked/set/StackedSet.java b/arithmetization/src/main/java/net/consensys/linea/zktracer/container/stacked/set/StackedSet.java
index 5f938b20b1..29541a8539 100644
--- a/arithmetization/src/main/java/net/consensys/linea/zktracer/container/stacked/set/StackedSet.java
+++ b/arithmetization/src/main/java/net/consensys/linea/zktracer/container/stacked/set/StackedSet.java
@@ -121,7 +121,7 @@ public <T> T[] toArray(@NotNull T[] a) {
 
   @Override
   public boolean add(E e) {
-    final boolean isNew = this.sets.peek().add(e);
+    final boolean isNew = this.sets.peekLast().add(e);
     if (isNew) {
       occurrences.put(e, occurrences.getOrDefault(e, 0) + 1);
     }