diff --git a/sys/dev/acpica/acpi_acad.c b/sys/dev/acpica/acpi_acad.c
index 38fd7c27847..85cd6665fd6 100644
--- a/sys/dev/acpica/acpi_acad.c
+++ b/sys/dev/acpica/acpi_acad.c
@@ -78,6 +78,9 @@ acpi_acad_get_status(void *context)
 	if (bootverbose) {
 		device_printf(dev,"%s\n",(sc->status) ? "On Line" : "Off Line");
 	}
+
+	/* set system power profile based on AC adapter status */
+	powerprofile_set_state(sc->status ? POWERPROFILE_PERFORMANCE : POWERPROFILE_ECONOMY);
 }
 
 static void
diff --git a/sys/dev/acpica/acpivar.h b/sys/dev/acpica/acpivar.h
index f529a4cded0..c2bf1afe0a3 100644
--- a/sys/dev/acpica/acpivar.h
+++ b/sys/dev/acpica/acpivar.h
@@ -267,11 +267,24 @@ extern int	acpi_avoid(ACPI_HANDLE handle);
 extern int	acpi_disabled(char *subsys);
 
 /*
- * Battery Abstruction and Generalized Power Management interface.
+ * Battery Abstruction.
  */
 struct acpi_battinfo;
 
 extern int	acpi_battery_register(int, int);
-extern int	acpi_acad_get_acline(void);
 extern int	acpi_cmbat_get_battinfo(int, struct acpi_battinfo *);
 
+/*
+ * System power API.
+ *
+ * XXX should this be further generalised?
+ *
+ */
+#define POWERPROFILE_PERFORMANCE	0
+#define POWERPROFILE_ECONOMY		1
+
+extern int	powerprofile_get_state(void);
+extern void	powerprofile_set_state(int state);
+
+typedef void (*powerprofile_change_hook)(void *);
+EVENTHANDLER_DECLARE(powerprofile_change, powerprofile_change_hook);