diff --git a/cbits/blake2/ref/blake2b-ref.c b/cbits/blake2/ref/blake2b-ref.c
index b6d30cf..c0b876c 100644
--- a/cbits/blake2/ref/blake2b-ref.c
+++ b/cbits/blake2/ref/blake2b-ref.c
@@ -99,7 +99,7 @@ int _cryptonite_blake2b_init( blake2b_state *S, size_t outlen )
 {
   blake2b_param P[1];
 
-  if ( ( !outlen ) || ( outlen > blake2B_OUTBYTES ) ) return -1;
+  if ( ( !outlen ) || ( outlen > BLAKE2B_OUTBYTES ) ) return -1;
 
   P->digest_length = (uint8_t)outlen;
   P->key_length    = 0;