diff --git a/app/src/colorwheel.cpp b/app/src/colorwheel.cpp
index 023a6448a..8100effe6 100644
--- a/app/src/colorwheel.cpp
+++ b/app/src/colorwheel.cpp
@@ -172,7 +172,7 @@ void ColorWheel::mouseReleaseEvent(QMouseEvent *)
 void ColorWheel::resizeEvent(QResizeEvent* event)
 {
     mWheelPixmap = QPixmap(event->size());
-    mWheelPixmap.fill(palette().background().color());
+    mWheelPixmap.fill(palette().window().color());
     drawWheelImage(event->size());
     drawSquareImage(mCurrentColor.hue());
 
diff --git a/app/src/preferencesdialog.cpp b/app/src/preferencesdialog.cpp
index a9941fe14..c2b8e79fe 100644
--- a/app/src/preferencesdialog.cpp
+++ b/app/src/preferencesdialog.cpp
@@ -562,7 +562,7 @@ void FilesPage::initPreset()
         QString name = mPresetSettings->value(key).toString();
         if (name.isEmpty())
             continue;
-        
+
         QListWidgetItem* item = new QListWidgetItem(name);
         item->setFlags(item->flags() | Qt::ItemIsEditable);
         item->setData(Qt::UserRole, index);
@@ -681,19 +681,19 @@ void FilesPage::updateValues()
 
     bool ok = true;
     int defaultPresetIndex = mManager->getInt(SETTING::DEFAULT_PRESET);
-    
+
     for (int i = 0; i < ui->presetListWidget->count(); i++)
     {
         QListWidgetItem* item = ui->presetListWidget->item(i);
         int presetIndex = item->data(Qt::UserRole).toInt(&ok);
 
         bool isDefault = presetIndex == defaultPresetIndex;
-        
+
         QFont font = item->font();
         font.setBold(isDefault); // Bold text for the default item
         item->setFont(font);
 
-        QBrush backgroundBrush = (isDefault) ? palette().light() : palette().background();
+        QBrush backgroundBrush = (isDefault) ? palette().light() : palette().window();
         item->setBackground(backgroundBrush);
     }
     ui->autosaveCheckBox->setChecked(mManager->isOn(SETTING::AUTO_SAVE));
@@ -729,7 +729,7 @@ ToolsPage::~ToolsPage()
 }
 
 void ToolsPage::updateValues()
-{    
+{
     ui->useQuickSizingBox->setChecked(mManager->isOn(SETTING::QUICK_SIZING));
     setRotationIncrement(mManager->getInt(SETTING::ROTATION_INCREMENT));
 }
diff --git a/core_lib/src/graphics/bitmap/bitmapimage.cpp b/core_lib/src/graphics/bitmap/bitmapimage.cpp
index 65e14782a..61b41df7e 100644
--- a/core_lib/src/graphics/bitmap/bitmapimage.cpp
+++ b/core_lib/src/graphics/bitmap/bitmapimage.cpp
@@ -436,7 +436,7 @@ void BitmapImage::autoCrop()
     int relRight = mBounds.width()-1;
 
     // Check left row
-    isEmpty = (relBottom >= relTop); // Check left only when 
+    isEmpty = (relBottom >= relTop); // Check left only when
     while (isEmpty && relBottom >= relTop && relLeft <= relRight) // Loop through columns
     {
         // Point cursor to the pixel at row relTop and column relLeft
@@ -628,7 +628,7 @@ void BitmapImage::drawPath(QPainterPath path, QPen pen, QBrush brush,
         painter.setPen(pen);
         painter.setBrush(brush);
         painter.setTransform(QTransform().translate(-mBounds.left(), -mBounds.top()));
-        painter.setMatrixEnabled(true);
+        painter.setWorldMatrixEnabled(true);
         if (path.length() > 0)
         {
             /*
@@ -714,7 +714,7 @@ Status BitmapImage::writeFile(const QString& filename)
         bool b = mImage->save(filename);
         return (b) ? Status::OK : Status::FAIL;
     }
-    
+
     if (bounds().isEmpty())
     {
         QFile f(filename);
diff --git a/core_lib/src/graphics/vector/beziercurve.cpp b/core_lib/src/graphics/vector/beziercurve.cpp
index 68671d448..1f5aac991 100644
--- a/core_lib/src/graphics/vector/beziercurve.cpp
+++ b/core_lib/src/graphics/vector/beziercurve.cpp
@@ -444,7 +444,7 @@ void BezierCurve::drawPath(QPainter& painter, Object* object, QTransform transfo
         qreal renderedWidth = width;
         if (simplified)
         {
-            renderedWidth = 1.0/painter.matrix().m11();
+            renderedWidth = 1.0/painter.worldTransform().m11();
 
             // Make sure the line width is positive.
             renderedWidth = fabs(renderedWidth);
@@ -483,7 +483,7 @@ void BezierCurve::drawPath(QPainter& painter, Object* object, QTransform transfo
         // highlight the selected elements
         colour = QColor(100,150,255);  // highlight colour
         painter.setBrush(Qt::NoBrush);
-        qreal lineWidth = 1.5/painter.matrix().m11();
+        qreal lineWidth = 1.5/painter.worldTransform().m11();
         lineWidth = fabs(lineWidth); // make sure line width is positive, otherwise nothing is drawn
         painter.setPen(QPen(QBrush(colour), lineWidth, Qt::SolidLine, Qt::RoundCap,Qt::RoundJoin));
         if (isSelected()) painter.drawPath(myCurve.getSimplePath());
diff --git a/core_lib/src/structure/object.cpp b/core_lib/src/structure/object.cpp
index 4a49caaf2..91e4fcf9e 100644
--- a/core_lib/src/structure/object.cpp
+++ b/core_lib/src/structure/object.cpp
@@ -812,7 +812,7 @@ bool Object::exportX(int frameStart, int frameEnd, QTransform view, QSize export
             xPainter.setWorldTransform(thumbView);
             xPainter.setClipRegion(thumbView.inverted().map(QRegion(target)));
             paintImage(xPainter, i, false, antialiasing);
-            xPainter.resetMatrix();
+            xPainter.resetTransform();
             xPainter.setClipping(false);
             xPainter.setPen(Qt::black);
             xPainter.drawRect(target);
diff --git a/core_lib/src/tool/strokemanager.h b/core_lib/src/tool/strokemanager.h
index 560be3606..043661d7a 100644
--- a/core_lib/src/tool/strokemanager.h
+++ b/core_lib/src/tool/strokemanager.h
@@ -25,7 +25,7 @@ GNU General Public License for more details.
 #include <time.h>
 #include <QTabletEvent>
 #include <QTimer>
-#include <QTime>
+#include <QElapsedTimer>
 #include "object.h"
 #include "assert.h"
 
@@ -76,7 +76,7 @@ class StrokeManager : public QObject
 
     QTimer timer;
 
-    QTime mSingleshotTime;
+    QElapsedTimer mSingleshotTime;
     QPointF mCurrentPressPixel = { 0, 0 };
     QPointF mLastPressPixel2 = { 0, 0 };
     QPointF mLastPressPixel = { 0, 0 };