diff --git a/hw/acpi/core.c b/hw/acpi/core.c
index 7925a1a..6a2f452 100644
--- a/hw/acpi/core.c
+++ b/hw/acpi/core.c
@@ -536,7 +536,6 @@
     ar->tmr.timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, acpi_pm_tmr_timer, ar);
     memory_region_init_io(&ar->tmr.io, memory_region_owner(parent),
                           &acpi_pm_tmr_ops, ar, "acpi-tmr", 4);
-    memory_region_clear_global_locking(&ar->tmr.io);
     memory_region_add_subregion(parent, 8, &ar->tmr.io);
 }