diff --git a/src/brushes/PencilBrush.ts b/src/brushes/PencilBrush.ts
index a1d39f2d3d6..a2d80640ecd 100644
--- a/src/brushes/PencilBrush.ts
+++ b/src/brushes/PencilBrush.ts
@@ -40,9 +40,9 @@ export class PencilBrush extends BaseBrush {
    */
   straightLineKey: ModifierKey | undefined | null = 'shiftKey';
 
-  private declare _points: Point[];
-  private declare _hasStraightLine: boolean;
-  private declare oldEnd?: Point;
+  protected declare _points: Point[];
+  protected declare _hasStraightLine: boolean;
+  protected declare oldEnd?: Point;
 
   constructor(canvas: Canvas) {
     super(canvas);