diff --git a/src/se050_hmac_blake2s.c b/src/se050_hmac_blake2s.c
index 0de7287..c5ba382 100644
--- a/src/se050_hmac_blake2s.c
+++ b/src/se050_hmac_blake2s.c
@@ -19,7 +19,7 @@ int se050_hmac_blake2s(uint8_t out[32],
     uint8_t inner_with_key[128];
     int i;
 
-    if (!out || !key || keylen == 0 || !data || datalen > 64) {
+    if (!out || !key || keylen == 0 || !data) {
         return -1;
     }