diff --git a/src/multimedia/video/qimagevideobuffer.cpp b/src/multimedia/video/qimagevideobuffer.cpp
index 59f708fed56ecaf717748c8179c3cbe5d1d678fb..f407e02d02236c5bc579362ca642f4411681166d 100644
--- a/src/multimedia/video/qimagevideobuffer.cpp
+++ b/src/multimedia/video/qimagevideobuffer.cpp
@@ -89,7 +89,7 @@ uchar *QImageVideoBuffer::map(MapMode mode, int *numBytes, int *bytesPerLine)
         d->mapMode = mode;
 
         if (numBytes)
-            *numBytes = d->image.byteCount();
+            *numBytes = int(d->image.sizeInBytes());
 
         if (bytesPerLine)
             *bytesPerLine = d->image.bytesPerLine();