diff --git a/tools/imagetool.h b/tools/imagetool.h
index 99bbf2f..ad2deb5 100644
--- a/tools/imagetool.h
+++ b/tools/imagetool.h
@@ -60,6 +60,7 @@
 	const char *comment;	/* Comment to add to signature node */
 	int require_keys;	/* 1 to mark signing keys as 'required' */
 	int file_size;		/* Total size of output file */
+	int orig_file_size;	/* Original size for file before padding */
 };
 
 /*