diff --git a/pc-bios/s390-ccw/cio.h b/pc-bios/s390-ccw/cio.h
index 55eaeee4b6..1a0795f645 100644
--- a/pc-bios/s390-ccw/cio.h
+++ b/pc-bios/s390-ccw/cio.h
@@ -125,7 +125,7 @@ struct tpi_info {
     __u32 reserved3  : 12;
     __u32 int_type   : 3;
     __u32 reserved4  : 12;
-} __attribute__ ((packed));
+} __attribute__ ((packed, aligned(4)));
 
 /* channel command word (type 1) */
 struct ccw1 {