diff --git a/libc/kernel/uapi/linux/fscrypt.h b/libc/kernel/uapi/linux/fscrypt.h
index ca42eb3..e6b5358 100644
--- a/libc/kernel/uapi/linux/fscrypt.h
+++ b/libc/kernel/uapi/linux/fscrypt.h
@@ -33,6 +33,7 @@
 #define FSCRYPT_MODE_AES_128_CBC 5
 #define FSCRYPT_MODE_AES_128_CTS 6
 #define FSCRYPT_MODE_ADIANTUM 9
+#define FSCRYPT_MODE_AES_256_HCTR2 10
 #define FSCRYPT_POLICY_V1 0
 #define FSCRYPT_KEY_DESCRIPTOR_SIZE 8
 struct fscrypt_policy_v1 {