diff --git a/ui/annotationtools.cpp b/ui/annotationtools.cpp
--- a/ui/annotationtools.cpp
+++ b/ui/annotationtools.cpp
@@ -176,8 +176,9 @@
         for ( ; pIt != pEnd; ++pIt )
         {
             Okular::NormalizedPoint pB = *pIt;
-            painter->drawLine( (int)(pA.x * (double)xScale), (int)(pA.y * (double)yScale),
-                               (int)(pB.x * (double)xScale), (int)(pB.y * (double)yScale) );
+            QPointF pAScaled( pA.x * xScale, pA.y * yScale );
+            QPointF pBScaled( pB.x * xScale, pB.y * yScale );
+            painter->drawLine( pAScaled, pBScaled );
             pA = pB;
         }
     }
diff --git a/ui/presentationwidget.cpp b/ui/presentationwidget.cpp
--- a/ui/presentationwidget.cpp
+++ b/ui/presentationwidget.cpp
@@ -897,16 +897,20 @@
 
         const QRect & geom = m_frames[ m_frameIndex ]->geometry;
 
-        QPixmap pm( geom.size() );
+        QPixmap pm( QSize( geom.size().width() * dpr, geom.size().height() * dpr ) );
         pm.fill( Qt::transparent );
         QPainter pmPainter( &pm );
 
+        pm.setDevicePixelRatio( dpr );
         pmPainter.setRenderHints( QPainter::Antialiasing );
+
+        // Paint old paths
         foreach ( const SmoothPath &drawing, m_frames[ m_frameIndex ]->drawings )
-            drawing.paint( &pmPainter, geom.width(), geom.height() );
+            drawing.paint( &pmPainter, dpr * geom.width(), dpr * geom.height() );
 
+        // Paint the path that is currently being drawn by the user
         if ( m_drawingEngine && m_drawingRect.intersects( pe->rect() ) )
-            m_drawingEngine->paint( &pmPainter, geom.width(), geom.height(), m_drawingRect.intersected( pe->rect() ) );
+            m_drawingEngine->paint( &pmPainter, dpr * geom.width(), dpr* geom.height(), m_drawingRect.intersected( pe->rect() ) );
 
         painter.setRenderHints( QPainter::Antialiasing );
         painter.drawPixmap( geom.topLeft() , pm );
@@ -1322,8 +1326,9 @@
     if ( eventType == AnnotatorEngine::Press )
         hasclicked = true;
 
-    double nX = ( (double)e->x() - (double)geom.left() ) / (double)geom.width();
-    double nY = ( (double)e->y() - (double)geom.top() ) / (double)geom.height();
+    QPointF mousePos = e->screenPos();
+    double nX = ( mousePos.x() - (double)geom.left() ) / (double)geom.width();
+    double nY = ( mousePos.y() - (double)geom.top() ) / (double)geom.height();
     QRect ret;
     bool isInside = nX >= 0 && nX < 1 && nY >= 0 && nY < 1;