diff --git a/toonz/sources/tnztools/toonzrasterbrushtool.cpp b/toonz/sources/tnztools/toonzrasterbrushtool.cpp
index 09dc759..b10005b 100644
--- a/toonz/sources/tnztools/toonzrasterbrushtool.cpp
+++ b/toonz/sources/tnztools/toonzrasterbrushtool.cpp
@@ -1380,9 +1380,9 @@ void ToonzRasterBrushTool::leftButtonDown(const TPointD &pos,
 
       if (m_smooth.getValue()) {
         std::vector<TThickPoint> pts;
-        m_smoothStroke.beginStroke(m_smooth.getValue());
-        m_smoothStroke.addPoint(thickPoint);
-        m_smoothStroke.getSmoothPoints(pts);
+        m_painting.smoothStroke.beginStroke(m_smooth.getValue());
+        m_painting.smoothStroke.addPoint(thickPoint);
+        m_painting.smoothStroke.getSmoothPoints(pts);
       }
     } else {
       m_painting.blured.points.clear();
@@ -1405,9 +1405,9 @@ void ToonzRasterBrushTool::leftButtonDown(const TPointD &pos,
 
       if (m_smooth.getValue()) {
         std::vector<TThickPoint> pts;
-        m_smoothStroke.beginStroke(m_smooth.getValue());
-        m_smoothStroke.addPoint(point);
-        m_smoothStroke.getSmoothPoints(pts);
+        m_painting.smoothStroke.beginStroke(m_smooth.getValue());
+        m_painting.smoothStroke.addPoint(point);
+        m_painting.smoothStroke.getSmoothPoints(pts);
       }
     }
     /*-- 作業中のFidを登録 --*/
@@ -1518,8 +1518,8 @@ void ToonzRasterBrushTool::leftButtonDrag(const TPointD &pos,
     if (m_smooth.getValue() == 0) {
       pts.push_back(thickPoint);
     } else {
-      m_smoothStroke.addPoint(thickPoint);
-      m_smoothStroke.getSmoothPoints(pts);
+      m_painting.smoothStroke.addPoint(thickPoint);
+      m_painting.smoothStroke.getSmoothPoints(pts);
     }
     for (size_t i = 0; i < pts.size(); ++i) {
       const TThickPoint &thickPoint = pts[i];
@@ -1547,8 +1547,8 @@ void ToonzRasterBrushTool::leftButtonDrag(const TPointD &pos,
     if (m_smooth.getValue() == 0) {
       pts.push_back(thickPoint);
     } else {
-      m_smoothStroke.addPoint(thickPoint);
-      m_smoothStroke.getSmoothPoints(pts);
+      m_painting.smoothStroke.addPoint(thickPoint);
+      m_painting.smoothStroke.getSmoothPoints(pts);
     }
     for (size_t i = 0; i < pts.size(); ++i) {
       TThickPoint old = m_painting.blured.points.back();
@@ -1708,9 +1708,9 @@ void ToonzRasterBrushTool::finishRasterBrush(const TPointD &pos,
     if (m_smooth.getValue() == 0 || m_painting.straight.isStraight) {
       pts.push_back(thickPoint);
     } else {
-      m_smoothStroke.addPoint(thickPoint);
-      m_smoothStroke.endStroke();
-      m_smoothStroke.getSmoothPoints(pts);
+      m_painting.smoothStroke.addPoint(thickPoint);
+      m_painting.smoothStroke.endStroke();
+      m_painting.smoothStroke.getSmoothPoints(pts);
     }
     for (size_t i = 0; i < pts.size(); ++i) {
       const TThickPoint &thickPoint = pts[i];
@@ -1760,9 +1760,9 @@ void ToonzRasterBrushTool::finishRasterBrush(const TPointD &pos,
     if (m_smooth.getValue() == 0 || m_painting.straight.isStraight) {
       pts.push_back(thickPoint);
     } else {
-      m_smoothStroke.addPoint(thickPoint);
-      m_smoothStroke.endStroke();
-      m_smoothStroke.getSmoothPoints(pts);
+      m_painting.smoothStroke.addPoint(thickPoint);
+      m_painting.smoothStroke.endStroke();
+      m_painting.smoothStroke.getSmoothPoints(pts);
     }
     // we need to skip the for-loop here if pts.size() == 0 or else
     // (pts.size() - 1) becomes ULLONG_MAX since size_t is unsigned
diff --git a/toonz/sources/tnztools/toonzrasterbrushtool.h b/toonz/sources/tnztools/toonzrasterbrushtool.h
index af8504f..7d688e5 100644
--- a/toonz/sources/tnztools/toonzrasterbrushtool.h
+++ b/toonz/sources/tnztools/toonzrasterbrushtool.h
@@ -185,6 +185,7 @@ protected:
     TTileSetCM32 *tileSet = nullptr;
     TTileSaverCM32 *tileSaver = nullptr;
     TRect lastRect;
+    SmoothStroke smoothStroke;
     
     struct Pencil {
       RasterStrokeGenerator *rasterTrack = nullptr;
@@ -234,8 +235,6 @@ protected:
   TRasterCM32P m_backupRas;
   TRaster32P m_workRas;
 
-  SmoothStroke m_smoothStroke;
-
   BrushPresetManager
       m_presetsManager;  //!< Manager for presets of this tool instance