diff --git a/src/Peachpie.Runtime/OrderedDictionary.cs b/src/Peachpie.Runtime/OrderedDictionary.cs
index e11d02cfad..3fdf9dddd2 100644
--- a/src/Peachpie.Runtime/OrderedDictionary.cs
+++ b/src/Peachpie.Runtime/OrderedDictionary.cs
@@ -1,8 +1,8 @@
 using System;
+using System.Buffers;
 using System.Collections;
 using System.Collections.Generic;
 using System.Diagnostics;
-using System.Linq;
 using System.Runtime.CompilerServices;
 using System.Threading;
 using Pchp.Core.Utilities;
@@ -188,6 +188,27 @@ public int CompareTo(IntStringKey other)
     [DebuggerDisplay("dictionary (count = {Count})")]
     public sealed class OrderedDictionary/*<TValue>*/ : IEnumerable<KeyValuePair<IntStringKey, TValue>>, IEnumerable<TValue>
     {
+        #region BucketPool
+
+        static class BucketPool
+        {
+            public static Bucket[] RentData(uint size) => ArrayPool<Bucket>.Shared.Rent(unchecked((int)size));
+
+            public static int[] RentHash(uint size) => ArrayPool<int>.Shared.Rent(unchecked((int)size));
+
+            public static void Return(Bucket[] array) => ArrayPool<Bucket>.Shared.Return(array, clearArray: true);
+
+            public static void Return(int[] array)
+            {
+                if (array != null)
+                {
+                    ArrayPool<int>.Shared.Return(array, clearArray: false);
+                }
+            }
+        }
+
+        #endregion
+
         [DebuggerDisplay("{DebugDisplay,nq}")]
         internal struct Bucket
         {
@@ -302,12 +323,19 @@ private OrderedDictionary(OrderedDictionary/*<TValue>*/ from)
             if (from == null) throw new ArgumentNullException(nameof(from));
 
             _mask = from._mask;
-            _data = from._data.AsSpan().ToArray();
-            if (from._hash != null)
-                _hash = from._hash.AsSpan().ToArray();
+            _size = from._size;
             _dataUsed = from._dataUsed;
+
+            _data = BucketPool.RentData(_size);
+            Array.Copy(from._data, 0, _data, 0, _dataUsed);
+            
+            if (from._hash != null)
+            {
+                _hash = BucketPool.RentHash(_size);
+                Array.Copy(from._hash, 0, _hash, 0, _size);
+            }
+
             _dataDeleted = from._dataDeleted;
-            _size = from._size;
             //nInternalPointer = from.nInternalPointer;
             _maxIntKey = from._maxIntKey;
         }
@@ -376,7 +404,7 @@ private void _initialize(uint mask)
             //
 
             _mask = mask;
-            _data = new Bucket[size];
+            _data = BucketPool.RentData(size);
             _hash = null; // no keys
             _dataUsed = 0;
             _dataDeleted = 0;
@@ -392,9 +420,13 @@ private void _resize(uint size)
 
             //Array.Resize(ref this._data, (int)size); // slower
 
-            var newdata = new Bucket[size];
+            var newdata = BucketPool.RentData(size);
+
             Array.Copy(_data, 0, newdata, 0, _dataUsed); // faster than Memory<T>.CopyTo() and Array.Resize<T>
-            _data = newdata;
+
+            BucketPool.Return(
+                Interlocked.Exchange(ref _data, newdata)
+            );
 
             _mask = size - 1;
             _size = size;
@@ -409,13 +441,13 @@ private void _resize(uint size)
 
         private void _rehash()
         {
-            var data = this._data;
-            var hash = this._hash;
+            var data = this._data.AsSpan(0, (int)_size);
+            var hash = this._hash.AsSpan(0, (int)_size);
 
-            Debug.Assert(hash != null, "no hash");
+            Debug.Assert(hash.Length != 0, "no hash");
             Debug.Assert(data.Length == hash.Length, "internal array size mismatch");
 
-            hash.AsSpan().Fill(_invalidIndex);  // some optimizations
+            hash.Fill(_invalidIndex);  // some optimizations
             //Array.Fill(hash, _invalidIndex);  // simple for-loop
 
             for (int i = this._dataUsed - 1; i >= 0; i--)
@@ -441,7 +473,10 @@ private void _rehash()
 
         private void _createhash()
         {
-            this._hash = new int[this._size];
+            BucketPool.Return(
+                Interlocked.Exchange(ref this._hash, BucketPool.RentHash(this._size))
+            );
+
             _rehash();
         }
 
@@ -1069,7 +1104,7 @@ public void CopyTo(TValue[] array, int arrayIndex)
             }
             // FastEnumerator does not have to be disposed
         }
-        
+
         /// <summary>
         /// Copy values into given array.
         /// </summary>
@@ -1107,7 +1142,7 @@ public void Shuffle(Random/*!*/generator)
 
             // shuffle and compact elements:
 
-            var newData = new Bucket[_size];
+            var newData = BucketPool.RentData(_size);
             var i = 0; // where to put next element
 
             var enumerator = GetEnumerator();
@@ -1131,7 +1166,10 @@ public void Shuffle(Random/*!*/generator)
                 i++;
             }
 
-            _data = newData;
+            BucketPool.Return(
+                Interlocked.Exchange(ref _data, newData) // _data = newData;
+            );
+
             _dataDeleted = 0;
             _dataUsed = i;
             //nInternalPointer = 0;
@@ -1140,7 +1178,7 @@ public void Shuffle(Random/*!*/generator)
 
             if (this._hash == null)
             {
-                this._hash = new int[this._size];
+                this._hash = BucketPool.RentHash(this._size);
             }
 
             _rehash();
@@ -1158,7 +1196,7 @@ public void Reverse()
 
             // copy elements in reverse order and compact:
 
-            var newData = new Bucket[_size];
+            var newData = BucketPool.RentData(_size);
             var i = Count; // where to put next element
 
             var enumerator = GetEnumerator();
@@ -1171,7 +1209,10 @@ public void Reverse()
                 bucket.Value = current.Value;
             }
 
-            _data = newData;
+            BucketPool.Return(
+                Interlocked.Exchange(ref _data, newData)
+            );
+
             _dataUsed = Count; // before changing _dataDeleted !!
             _dataDeleted = 0;
             //nInternalPointer = 0;
@@ -1180,7 +1221,7 @@ public void Reverse()
 
             if (this._hash == null)
             {
-                this._hash = new int[this._size];
+                this._hash = BucketPool.RentHash(this._size);
             }
 
             _rehash();
@@ -1236,7 +1277,7 @@ public void Sort(IComparer<KeyValuePair<IntStringKey, TValue>>/*!*/comparer)
                 {
                     if (this._hash == null)
                     {
-                        this._hash = new int[this._size];
+                        this._hash = BucketPool.RentHash(this._size);
                     }
 
                     _rehash();
@@ -1251,9 +1292,12 @@ sealed class MultisortComparer : IComparer<Bucket[]>
         {
             readonly IComparer<KeyValuePair<IntStringKey, TValue>>[]/*!*/ comparers;
 
-            public MultisortComparer(IComparer<KeyValuePair<IntStringKey, TValue>>[]/*!*/ comparers)
+            readonly int length;
+
+            public MultisortComparer(IComparer<KeyValuePair<IntStringKey, TValue>>[]/*!*/ comparers, int length)
             {
                 this.comparers = comparers;
+                this.length = length;
             }
 
             public int Compare(Bucket[] x, Bucket[] y)
@@ -1310,7 +1354,7 @@ public static void Sort(
             }
 
             // sort indices
-            Array.Sort(idx, comparer: new MultisortComparer(comparers));
+            Array.Sort(idx, comparer: new MultisortComparer(comparers, hashtables.Length));
 
             //
             for (int h = 0; h < hashtables.Length; h++)