diff --git a/openwrt/package/openwrt/jffs2root.c b/openwrt/package/openwrt/jffs2root.c
index aa718da5930..36b928ff46e 100644
--- a/openwrt/package/openwrt/jffs2root.c
+++ b/openwrt/package/openwrt/jffs2root.c
@@ -99,7 +99,7 @@ int main(int argc, char **argv)
         printf("Partition already moved outside trx\n");
       } else {
 	init_crc32();
-	ptr->offsets[2] += mtdInfo.erasesize;
+	ptr->offsets[2] +=  (mtdInfo.erasesize - 1);
 	ptr->offsets[2] &= ~(mtdInfo.erasesize - 1);
         ptr->len = ptr->offsets[2];
         ptr->crc32 = crc32buf((void *) &(ptr->flag_version), ptr->len - offsetof(struct trx_header, flag_version));