diff --git a/hw/s390x/ipl.c b/hw/s390x/ipl.c
index 132004a..2e0a8b6 100644
--- a/hw/s390x/ipl.c
+++ b/hw/s390x/ipl.c
@@ -218,7 +218,7 @@
  * - -1 if no valid boot device was found
  * - ccw id of the boot device otherwise
  */
-static uint32_t s390_update_iplstate(CPUS390XState *env, S390IPLState *ipl)
+static uint64_t s390_update_iplstate(CPUS390XState *env, S390IPLState *ipl)
 {
     DeviceState *dev_st;
 
@@ -248,7 +248,7 @@
 
     return -1;
 out:
-    return ipl->cssid << 24 | ipl->ssid << 16 | ipl->devno;
+    return (uint32_t) (ipl->cssid << 24 | ipl->ssid << 16 | ipl->devno);
 }
 
 int s390_ipl_update_diag308(IplParameterBlock *iplb)