diff --git a/lcl/interfaces/win32/win32winapi.inc b/lcl/interfaces/win32/win32winapi.inc
index 97166c5a62..68cfe15ed2 100644
--- a/lcl/interfaces/win32/win32winapi.inc
+++ b/lcl/interfaces/win32/win32winapi.inc
@@ -1735,7 +1735,7 @@ begin
     ARect.Right := BitmapInfo.bmWidth;
 
   // copy bitmap
-  AllocAndCopy(BitmapInfo, ARect, NewRawImage.Data, NewRawImage.MaskSize);
+  AllocAndCopy(BitmapInfo, ARect, NewRawImage.Data, NewRawImage.DataSize);
 
   // check mask
   if SrcMaskBitmap <> 0 then