diff --git a/src/plugins/platforms/cocoa/qnsview.mm b/src/plugins/platforms/cocoa/qnsview.mm
index 1f19b07904..f0ece54d20 100644
--- a/src/plugins/platforms/cocoa/qnsview.mm
+++ b/src/plugins/platforms/cocoa/qnsview.mm
@@ -316,6 +316,7 @@ static QTouchDevice *touchDevice = 0;
     );
     CGImageRef bsCGImage = m_backingStore->getBackingStoreCGImage();
     CGImageRef cleanImg = CGImageCreateWithImageInRect(bsCGImage, backingStoreRect);
+    CGContextSetBlendMode(cgContext, kCGBlendModeCopy);
     CGContextDrawImage(cgContext, dirtyWindowRect, cleanImg);
 
     // Clean-up: