diff --git a/src/gui/image/qimage.cpp b/src/gui/image/qimage.cpp
index e33ab24243..dba42d4698 100644
--- a/src/gui/image/qimage.cpp
+++ b/src/gui/image/qimage.cpp
@@ -1433,6 +1433,10 @@ void QImage::setDevicePixelRatio(qreal scaleFactor)
 {
     if (!d)
         return;
+
+    if (scaleFactor == d->devicePixelRatio)
+        return;
+
     detach();
     d->devicePixelRatio = scaleFactor;
 }
diff --git a/src/gui/image/qpixmap.cpp b/src/gui/image/qpixmap.cpp
index 0a9b55ed24..db6ae54d26 100644
--- a/src/gui/image/qpixmap.cpp
+++ b/src/gui/image/qpixmap.cpp
@@ -682,6 +682,9 @@ void QPixmap::setDevicePixelRatio(qreal scaleFactor)
     if (isNull())
         return;
 
+    if (scaleFactor == data->devicePixelRatio())
+        return;
+
     detach();
     data->setDevicePixelRatio(scaleFactor);
 }