diff --git a/fs/btrfs/crypto/hash.h b/fs/btrfs/crypto/hash.h
index d1ba1fa..f984603 100644
--- a/fs/btrfs/crypto/hash.h
+++ b/fs/btrfs/crypto/hash.h
@@ -9,6 +9,7 @@
 int hash_crc32c(const u8 *buf, size_t length, u8 *out);
 int hash_xxhash(const u8 *buf, size_t length, u8 *out);
 int hash_sha256(const u8 *buf, size_t length, u8 *out);
+int hash_blake2(const u8 *buf, size_t length, u8 *out);
 
 u32 crc32c(u32 seed, const void * data, size_t len);