diff --git a/src/jpgimage.cpp b/src/jpgimage.cpp
index fb63b309..5997f832 100644
--- a/src/jpgimage.cpp
+++ b/src/jpgimage.cpp
@@ -1082,7 +1082,7 @@ namespace Exiv2 {
                             throw Error(kerImageWriteFailed);
 
                         // Write new Exif data buffer
-                        if (outIo.write(pExifData, exifSize) != static_cast<long>(exifSize))
+                        if (outIo.write(pExifData, static_cast<long>(exifSize)) != static_cast<long>(exifSize))
                             throw Error(kerImageWriteFailed);
                         if (outIo.error())
                             throw Error(kerImageWriteFailed);