diff --git a/src/hw/virtio-blk.c b/src/hw/virtio-blk.c
index 9b4a05a..ce3265e 100644
--- a/src/hw/virtio-blk.c
+++ b/src/hw/virtio-blk.c
@@ -92,7 +92,7 @@
     u16 blk_num_max;
 
     if (vdrive->drive.blksize != 0 && max_io_size != 0)
-        blk_num_max = (u16)max_io_size / vdrive->drive.blksize;
+        blk_num_max = (u16)(max_io_size / vdrive->drive.blksize);
     else
         /* default blk_num_max if hardware doesnot advise a proper value */
         blk_num_max = 64;