diff --git a/src/ZoneTree.UnitTests/SafeBplusTreeTests.cs b/src/ZoneTree.UnitTests/SafeBplusTreeTests.cs
index ad5c4a6..a6f8ac3 100644
--- a/src/ZoneTree.UnitTests/SafeBplusTreeTests.cs
+++ b/src/ZoneTree.UnitTests/SafeBplusTreeTests.cs
@@ -148,15 +148,13 @@ public void BTreeIteratorParallelInserts(BTreeLockMode lockMode)
             {
                 var key = random.Next();
                 tree.AddOrUpdate(key,
-                    AddOrUpdateResult (ref int value) =>
+                    void (ref int value) =>
                     {
                         value = key + key;
-                        return AddOrUpdateResult.ADDED;
                     },
-                    AddOrUpdateResult (ref int value) =>
+                    void (ref int value) =>
                     {
                         value = key + key;
-                        return AddOrUpdateResult.UPDATED;
                     }, out _);
             });
         });
@@ -203,15 +201,13 @@ public void BTreeReverseIteratorParallelInserts(BTreeLockMode lockMode)
             {
                 var key = random.Next();
                 tree.AddOrUpdate(key,
-                    AddOrUpdateResult (ref int x) =>
+                    void (ref int x) =>
                     {
                         x = key + key;
-                        return AddOrUpdateResult.ADDED;
                     },
-                    AddOrUpdateResult (ref int y) =>
+                    void (ref int y) =>
                     {
                         y = key + key;
-                        return AddOrUpdateResult.UPDATED;
                     }, out _);
             });
         });
diff --git a/src/ZoneTree/Collections/BTree/BTree.Write.cs b/src/ZoneTree/Collections/BTree/BTree.Write.cs
index 6a1f816..3918c4b 100644
--- a/src/ZoneTree/Collections/BTree/BTree.Write.cs
+++ b/src/ZoneTree/Collections/BTree/BTree.Write.cs
@@ -95,9 +95,9 @@ public bool TryInsert(in TKey key, in TValue value, out long opIndex)
         }
     }
 
-    public delegate AddOrUpdateResult AddDelegate(ref TValue value);
+    public delegate void AddDelegate(ref TValue value);
 
-    public delegate AddOrUpdateResult UpdateDelegate(ref TValue value);
+    public delegate void UpdateDelegate(ref TValue value);
 
     public AddOrUpdateResult AddOrUpdate(
         in TKey key,
diff --git a/src/ZoneTree/Segments/InMemory/MutableSegment.cs b/src/ZoneTree/Segments/InMemory/MutableSegment.cs
index 1e80d9b..89671dd 100644
--- a/src/ZoneTree/Segments/InMemory/MutableSegment.cs
+++ b/src/ZoneTree/Segments/InMemory/MutableSegment.cs
@@ -224,17 +224,15 @@ public AddOrUpdateResult Delete(in TKey key, out long opIndex)
 
             var status = BTree
                 .AddOrUpdate(key,
-                    AddOrUpdateResult (ref TValue x) =>
+                    void (ref TValue x) =>
                     {
                         MarkValueDeleted(ref x);
                         insertedValue = x;
-                        return AddOrUpdateResult.ADDED;
                     },
-                    AddOrUpdateResult (ref TValue x) =>
+                    void (ref TValue x) =>
                     {
                         MarkValueDeleted(ref x);
                         insertedValue = x;
-                        return AddOrUpdateResult.UPDATED;
                     }, out opIndex);
             WriteAheadLog.Append(in key, in insertedValue, opIndex);
             return status;