diff --git a/Memola/Canvas/Contexts/GraphicContext.swift b/Memola/Canvas/Contexts/GraphicContext.swift
index 8cdd836..38dc787 100644
--- a/Memola/Canvas/Contexts/GraphicContext.swift
+++ b/Memola/Canvas/Contexts/GraphicContext.swift
@@ -59,7 +59,7 @@ final class GraphicContext: @unchecked Sendable {
                 eraserStrokes.remove(eraserStroke)
                 withPersistence(\.backgroundContext) { [weak eraserStroke] context in
                     guard let eraserStroke else { return }
-                    for penStroke in eraserStroke.penStrokes {
+                    for penStroke in eraserStroke.penStrokes.allObjects {
                         penStroke.eraserStrokes.remove(eraserStroke)
                         if let object = eraserStroke.object {
                             penStroke.object?.erasers.remove(object)
@@ -94,7 +94,7 @@ final class GraphicContext: @unchecked Sendable {
                 eraserStrokes.insert(eraserStroke)
                 withPersistence(\.backgroundContext) { [weak eraserStroke] context in
                     guard let eraserStroke else { return }
-                    for penStroke in eraserStroke.penStrokes {
+                    for penStroke in eraserStroke.penStrokes.allObjects {
                         penStroke.eraserStrokes.insert(eraserStroke)
                         if let object = eraserStroke.object {
                             penStroke.object?.erasers.add(object)
diff --git a/Memola/Canvas/Geometries/Stroke/Strokes/EraserStroke.swift b/Memola/Canvas/Geometries/Stroke/Strokes/EraserStroke.swift
index c9552ad..a4a2451 100644
--- a/Memola/Canvas/Geometries/Stroke/Strokes/EraserStroke.swift
+++ b/Memola/Canvas/Geometries/Stroke/Strokes/EraserStroke.swift
@@ -34,7 +34,7 @@ final class EraserStroke: Stroke, @unchecked Sendable {
     weak var graphicContext: GraphicContext?
 
     var finishesSaving: Bool = false
-    var penStrokes: Set<PenStroke> = []
+    var penStrokes: NSHashTable<PenStroke> = .weakObjects()
 
     init(
         bounds: [CGFloat],
@@ -112,7 +112,7 @@ final class EraserStroke: Stroke, @unchecked Sendable {
                 for stroke in graphicContext.tree.search(box: _quad.quadBox) {
                     if let _penStroke = stroke.stroke(as: PenStroke.self), !_penStroke.eraserStrokes.contains(self) {
                         _penStroke.eraserStrokes.insert(self)
-                        penStrokes.insert(_penStroke)
+                        penStrokes.add(_penStroke)
                         if let penStroke = _penStroke.object {
                             penStroke.erasers.add(eraser)
                             eraser.strokes.add(penStroke)