diff --git a/src/EcsAspect.cs b/src/EcsAspect.cs
index fa19726..589ae24 100644
--- a/src/EcsAspect.cs
+++ b/src/EcsAspect.cs
@@ -353,16 +353,16 @@ namespace DCFApixels.DragonECS
                 private UnsafeArray<EcsMaskChunck> _sortIncChunckBuffer;
                 private UnsafeArray<EcsMaskChunck> _sortExcChunckBuffer;
 
-                private readonly int _entityComponentMaskLength;
+                private readonly int _entityComponentMaskBitShift;
 
                 public unsafe Enumerator(EcsSpan span, EcsAspect aspect)
                 {
-                    _span = span.GetEnumerator();
                     _entityComponentMasks = aspect.World._entityComponentMasks;
                     _sortIncChunckBuffer = aspect._sortIncChunckBuffer;
                     _sortExcChunckBuffer = aspect._sortExcChunckBuffer;
 
-                    _entityComponentMaskLength = aspect.World._entityComponentMaskLength;
+                    _entityComponentMaskBitShift = aspect.World._entityComponentMaskLength;
+                    _entityComponentMaskBitShift = BitsUtility.GetHighBitNumber(_entityComponentMaskBitShift);
 
                     #region Sort
                     UnsafeArray<int> _sortIncBuffer = aspect._sortIncBuffer;
@@ -403,7 +403,11 @@ namespace DCFApixels.DragonECS
                             }
                         }
                     }
-
+                    if (_sortIncChunckBuffer.Length > 0 && counts[_sortIncBuffer.ptr[0]] <= 0)
+                    {
+                        _span = span.Slice(0, 0).GetEnumerator();
+                        return;
+                    }
                     if (_sortExcChunckBuffer.Length > 1)
                     {
                         ExcCountComparer excComparer = new ExcCountComparer(counts);
@@ -434,6 +438,7 @@ namespace DCFApixels.DragonECS
                         }
                     }
                     #endregion
+                    _span = span.GetEnumerator();
                 }
                 public int Current
                 {
@@ -445,11 +450,11 @@ namespace DCFApixels.DragonECS
                 {
                     while (_span.MoveNext())
                     {
-                        int e = _span.Current;
+                        int chunck = _span.Current << _entityComponentMaskBitShift;
                         for (int i = 0; i < _sortIncChunckBuffer.Length; i++)
                         {
                             var bit = _sortIncChunckBuffer.ptr[i];
-                            if ((_entityComponentMasks[e * _entityComponentMaskLength + bit.chankIndex] & bit.mask) != bit.mask)
+                            if ((_entityComponentMasks[chunck + bit.chankIndex] & bit.mask) != bit.mask)
                             {
                                 goto skip;
                             }
@@ -457,7 +462,7 @@ namespace DCFApixels.DragonECS
                         for (int i = 0; i < _sortExcChunckBuffer.Length; i++)
                         {
                             var bit = _sortExcChunckBuffer.ptr[i];
-                            if ((_entityComponentMasks[e * _entityComponentMaskLength + bit.chankIndex] & bit.mask) > 0)
+                            if ((_entityComponentMasks[chunck + bit.chankIndex] & bit.mask) != 0)
                             {
                                 goto skip;
                             }
diff --git a/src/EcsWorld.cs b/src/EcsWorld.cs
index 798e2a5..b1900a1 100644
--- a/src/EcsWorld.cs
+++ b/src/EcsWorld.cs
@@ -544,12 +544,17 @@ namespace DCFApixels.DragonECS
         {
             _entityDispenser.Upsize(minSize);
         }
+        private int CalcEntityComponentMaskLastIndex()
+        {
+            int result = _pools.Length / COMPONENT_MASK_CHUNK_SIZE;
+            return (result < 2 ? 2 : result);
+        }
         [MethodImpl(MethodImplOptions.NoInlining)]
         private void OnEntityDispenserResized(int newSize)
         {
             Array.Resize(ref _entities, newSize);
             Array.Resize(ref _delEntBuffer, newSize);
-            _entityComponentMaskLength = _pools.Length / COMPONENT_MASK_CHUNK_SIZE + 1;
+            _entityComponentMaskLength = CalcEntityComponentMaskLastIndex();//_pools.Length / COMPONENT_MASK_CHUNK_SIZE + 1;
             Array.Resize(ref _entityComponentMasks, newSize * _entityComponentMaskLength);
 
             ArrayUtility.Fill(_entities, EntitySlot.Empty, _entitiesCapacity);
diff --git a/src/EcsWorld.pools.cs b/src/EcsWorld.pools.cs
index ee980cd..95ab769 100644
--- a/src/EcsWorld.pools.cs
+++ b/src/EcsWorld.pools.cs
@@ -166,7 +166,7 @@ namespace DCFApixels.DragonECS
                 Array.Resize(ref _poolComponentCounts, _pools.Length);
                 ArrayUtility.Fill(_pools, _nullPool, oldCapacity, oldCapacity - _pools.Length);
 
-                int newEntityComponentMaskLength = _pools.Length / COMPONENT_MASK_CHUNK_SIZE + 1;
+                int newEntityComponentMaskLength = CalcEntityComponentMaskLastIndex(); //_pools.Length / COMPONENT_MASK_CHUNK_SIZE + 1;
                 int dif = newEntityComponentMaskLength - _entityComponentMaskLength;
                 if (dif > 0)
                 {