diff --git a/libc/kernel/uapi/linux/futex.h b/libc/kernel/uapi/linux/futex.h
index 6176f38..aa0dac1 100644
--- a/libc/kernel/uapi/linux/futex.h
+++ b/libc/kernel/uapi/linux/futex.h
@@ -33,6 +33,7 @@
 #define FUTEX_WAKE_BITSET 10
 #define FUTEX_WAIT_REQUEUE_PI 11
 #define FUTEX_CMP_REQUEUE_PI 12
+#define FUTEX_LOCK_PI2 13
 #define FUTEX_PRIVATE_FLAG 128
 #define FUTEX_CLOCK_REALTIME 256
 #define FUTEX_CMD_MASK ~(FUTEX_PRIVATE_FLAG | FUTEX_CLOCK_REALTIME)
@@ -42,6 +43,7 @@
 #define FUTEX_CMP_REQUEUE_PRIVATE (FUTEX_CMP_REQUEUE | FUTEX_PRIVATE_FLAG)
 #define FUTEX_WAKE_OP_PRIVATE (FUTEX_WAKE_OP | FUTEX_PRIVATE_FLAG)
 #define FUTEX_LOCK_PI_PRIVATE (FUTEX_LOCK_PI | FUTEX_PRIVATE_FLAG)
+#define FUTEX_LOCK_PI2_PRIVATE (FUTEX_LOCK_PI2 | FUTEX_PRIVATE_FLAG)
 #define FUTEX_UNLOCK_PI_PRIVATE (FUTEX_UNLOCK_PI | FUTEX_PRIVATE_FLAG)
 #define FUTEX_TRYLOCK_PI_PRIVATE (FUTEX_TRYLOCK_PI | FUTEX_PRIVATE_FLAG)
 #define FUTEX_WAIT_BITSET_PRIVATE (FUTEX_WAIT_BITSET | FUTEX_PRIVATE_FLAG)