diff --git a/sys/dev/acpi_support/acpi_wmi.c b/sys/dev/acpi_support/acpi_wmi.c
--- a/sys/dev/acpi_support/acpi_wmi.c
+++ b/sys/dev/acpi_support/acpi_wmi.c
@@ -976,8 +976,7 @@
 	sc = dev->si_drv1;
 
 	ACPI_SERIAL_BEGIN(acpi_wmi);
-	if (sc->wmistat_open_pid != buf->uio_td->td_proc->p_pid ||
-			sc->wmistat_bufptr == -1) {
+	if (sc->wmistat_bufptr == -1) {
 		ret = EBADF;
 	}
 	else {