diff --git a/hw/s390x/event-facility.c b/hw/s390x/event-facility.c
index a73c0b9..1e8c99a 100644
--- a/hw/s390x/event-facility.c
+++ b/hw/s390x/event-facility.c
@@ -299,7 +299,7 @@
 
 static void command_handler(SCLPEventFacility *ef, SCCB *sccb, uint64_t code)
 {
-    switch (code) {
+    switch (code & SCLP_CMD_CODE_MASK) {
     case SCLP_CMD_READ_EVENT_DATA:
         read_event_data(ef, sccb);
         break;