diff --git a/sys/geom/geom_io.c b/sys/geom/geom_io.c
index 0b8e118..7e08640 100644
--- a/sys/geom/geom_io.c
+++ b/sys/geom/geom_io.c
@@ -358,6 +358,14 @@ g_io_check(struct bio *bp)
 			return (EIO);
 		if (bp->bio_offset > pp->mediasize)
 			return (EIO);
+		/* Reject request with unaligned buffers */
+		if (((bp->bio_flags & BIO_UNMAPPED) != 0 &&
+		    bp->bio_ma_offset % pp->sectorsize != 0) ||
+		    ((bp->bio_flags & BIO_UNMAPPED) == 0 &&
+		    (vm_offset_t)bp->bio_data % pp->sectorsize != 0)) {
+			printf("Rejecting bios with unaligned buffer\n");
+			return (EINVAL);
+		}
 
 		/* Truncate requests to the end of providers media. */
 		excess = bp->bio_offset + bp->bio_length;