diff --git a/options/linux/include/scsi/sg.h b/options/linux/include/scsi/sg.h
index 19ad469519..26616756d8 100644
--- a/options/linux/include/scsi/sg.h
+++ b/options/linux/include/scsi/sg.h
@@ -33,7 +33,7 @@ typedef struct sg_io_hdr {
     unsigned int dxfer_len;
     void *dxferp;
     unsigned char *cmdp;
-    void *sbp;
+    unsigned char *sbp;
     unsigned int timeout;
     unsigned int flags;
     int pack_id;