diff --git a/sys/dev/acpica/acpi.c b/sys/dev/acpica/acpi.c
index c0724bc15021..bd7faab39b95 100644
--- a/sys/dev/acpica/acpi.c
+++ b/sys/dev/acpica/acpi.c
@@ -331,14 +331,14 @@ acpi_identify(driver_t *driver, device_t parent)
     if (device_find_child(parent, "acpi", 0) != NULL)
 	return_VOID;
 
+    snprintf(acpi_ca_version, sizeof(acpi_ca_version), "%x", ACPI_CA_VERSION);
+
     /* Initialize root tables. */
     if (ACPI_FAILURE(acpi_Startup())) {
 	printf("ACPI: Try disabling either ACPI or apic support.\n");
 	return_VOID;
     }
 
-    snprintf(acpi_ca_version, sizeof(acpi_ca_version), "%x", ACPI_CA_VERSION);
-
     /* Attach the actual ACPI device. */
     if ((child = BUS_ADD_CHILD(parent, 10, "acpi", 0)) == NULL) {
 	device_printf(parent, "device_identify failed\n");