diff --git a/hw/acpi.c b/hw/acpi.c
index 1129335599..407949bfa0 100644
--- a/hw/acpi.c
+++ b/hw/acpi.c
@@ -268,6 +268,11 @@ void acpi_pm1_evt_write_sts(ACPIREGS *ar, uint16_t val)
     ar->pm1.evt.sts &= ~val;
 }
 
+void acpi_pm1_evt_write_en(ACPIREGS *ar, uint16_t val)
+{
+    ar->pm1.evt.en = val;
+}
+
 void acpi_pm1_evt_power_down(ACPIREGS *ar)
 {
     if (ar->pm1.evt.en & ACPI_BITMASK_POWER_BUTTON_ENABLE) {
diff --git a/hw/acpi.h b/hw/acpi.h
index e1d5e3b0cd..88f805119c 100644
--- a/hw/acpi.h
+++ b/hw/acpi.h
@@ -133,6 +133,7 @@ static inline int64_t acpi_pm_tmr_get_clock(void)
 /* PM1a_EVT: piix and ich9 don't implement PM1b. */
 uint16_t acpi_pm1_evt_get_sts(ACPIREGS *ar);
 void acpi_pm1_evt_write_sts(ACPIREGS *ar, uint16_t val);
+void acpi_pm1_evt_write_en(ACPIREGS *ar, uint16_t val);
 void acpi_pm1_evt_power_down(ACPIREGS *ar);
 void acpi_pm1_evt_reset(ACPIREGS *ar);
 
diff --git a/hw/acpi_piix4.c b/hw/acpi_piix4.c
index 5b16d2039c..164122977e 100644
--- a/hw/acpi_piix4.c
+++ b/hw/acpi_piix4.c
@@ -117,7 +117,7 @@ static void pm_ioport_write(IORange *ioport, uint64_t addr, unsigned width,
         pm_update_sci(s);
         break;
     case 0x02:
-        s->ar.pm1.evt.en = val;
+        acpi_pm1_evt_write_en(&s->ar, val);
         pm_update_sci(s);
         break;
     case 0x04:
diff --git a/hw/vt82c686.c b/hw/vt82c686.c
index 1b083de097..a53bd8ad0f 100644
--- a/hw/vt82c686.c
+++ b/hw/vt82c686.c
@@ -206,7 +206,7 @@ static void pm_ioport_writew(void *opaque, uint32_t addr, uint32_t val)
         pm_update_sci(s);
         break;
     case 0x02:
-        s->ar.pm1.evt.en = val;
+        acpi_pm1_evt_write_en(&s->ar, val);
         pm_update_sci(s);
         break;
     case 0x04: