diff --git a/src/mainboard/apple/macbook21/mainboard.c b/src/mainboard/apple/macbook21/mainboard.c
index 6bd3aec083..e244af412d 100644
--- a/src/mainboard/apple/macbook21/mainboard.c
+++ b/src/mainboard/apple/macbook21/mainboard.c
@@ -67,9 +67,16 @@ static int int15_handler(void)
 }
 #endif
 
+static acpi_cstate_t cst_entries[] = {
+	{ 1,  1, 1000, { 0x7f, 1, 2, { 0 }, 0, 0 } },
+	{ 2,  1,  500, { 0x7f, 1, 2, { 0 }, 0x10, 0 } },
+	{ 2, 55,  100, { 0x7f, 1, 2, { 0 }, 0x31, 0 } },
+};
+
 int get_cst_entries(acpi_cstate_t **entries)
 {
-	return 0;
+	*entries = cst_entries;
+	return ARRAY_SIZE(cst_entries);
 }
 
 static void mainboard_init(device_t dev)