diff --git a/magick/blob-private.h b/magick/blob-private.h
index 829a16d..7dfc4d6 100644
--- a/magick/blob-private.h
+++ b/magick/blob-private.h
@@ -84,7 +84,8 @@
   TellBlob(const Image *);
 
 extern MagickExport MagickSizeType
-  ReadBlobLongLong(Image *);
+  ReadBlobLongLong(Image *),
+  ReadBlobMSBLongLong(Image *);
 
 extern MagickExport ssize_t
   ReadBlob(Image *,const size_t,unsigned char *),