diff --git a/sys/dev/acpica/acpi_hpet.c b/sys/dev/acpica/acpi_hpet.c
--- a/sys/dev/acpica/acpi_hpet.c
+++ b/sys/dev/acpica/acpi_hpet.c
@@ -421,7 +421,7 @@
 	int		i;
 
 	/* Only one HPET device can be added. */
-	if (devclass_get_device(hpet_devclass, 0))
+	if (devclass_get_device(devclass_find("hpet"), 0))
 		return;
 	for (i = 1; ; i++) {
 		/* Search for HPET table. */