diff --git a/src/mainboard/apple/macbook21/mainboard.c b/src/mainboard/apple/macbook21/mainboard.c
index 9a025dd..a2adb76 100644
--- a/src/mainboard/apple/macbook21/mainboard.c
+++ b/src/mainboard/apple/macbook21/mainboard.c
@@ -40,6 +40,12 @@
 extern const u32 *cim_verb_data;
 extern u32 cim_verb_data_size;
 
+static acpi_cstate_t cst_entries[] = {
+        { 1,  1, 1000, { 0x7f, 1, 2, { 0 }, 1, 0 } },
+        { 2,  1,  500, { 0x01, 8, 0, { 0 }, DEFAULT_PMBASE + LV2, 0 } },
+        { 2, 17,  250, { 0x01, 8, 0, { 0 }, DEFAULT_PMBASE + LV3, 0 } },
+};
+
 #if CONFIG_PCI_OPTION_ROM_RUN_YABEL || CONFIG_PCI_OPTION_ROM_RUN_REALMODE
 static int int15_handler(void)
 {
@@ -73,7 +79,8 @@ static int int15_handler(void)
 
 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)

