diff --git a/src/gui/UBSpinningWheel.cpp b/src/gui/UBSpinningWheel.cpp
index 94197697..185420bf 100644
--- a/src/gui/UBSpinningWheel.cpp
+++ b/src/gui/UBSpinningWheel.cpp
@@ -64,7 +64,7 @@ void UBSpinningWheel::paintEvent(QPaintEvent *event)
     pen.setCapStyle(Qt::RoundCap);
 
     painter.setPen(pen);
-    painter.rotate(30 * (mPosition % 12));
+    painter.rotate(30 * (mPosition.loadAcquire() % 12));
 
     for(int i = 0; i < 12; i++)
     {
diff --git a/src/pdf/PDFRenderer.cpp b/src/pdf/PDFRenderer.cpp
index 1deaac5c..5fdc09c3 100644
--- a/src/pdf/PDFRenderer.cpp
+++ b/src/pdf/PDFRenderer.cpp
@@ -26,6 +26,7 @@
 
 
 #include <QFile>
+#include <QDesktopWidget>
 
 #include "PDFRenderer.h"
 
@@ -97,7 +98,7 @@ void PDFRenderer::attach()
 void PDFRenderer::detach()
 {
     mRefCount.deref();
-    if (mRefCount == 0)
+    if (mRefCount.loadAcquire() == 0)
     {
         sRenderers.remove(mFileUuid);
         delete this;
diff --git a/src/pdf/XPDFRenderer.cpp b/src/pdf/XPDFRenderer.cpp
index f6040675..6c65ce9e 100644
--- a/src/pdf/XPDFRenderer.cpp
+++ b/src/pdf/XPDFRenderer.cpp
@@ -66,7 +66,7 @@ XPDFRenderer::~XPDFRenderer()
         sInstancesCount.deref();
     }
 
-    if (sInstancesCount == 0 && globalParams)
+    if (sInstancesCount.loadAcquire() == 0 && globalParams)
     {
         delete globalParams;
         globalParams = 0;