diff --git a/crypto/blake2/m_blake2b.c b/crypto/blake2/m_blake2b.c
index 2135c7a1295c1f49dfc4d44d192f8d2656bc1d73..f613bfff171d9a93ad8eaa6f56f24b3e2be39dd2 100644
--- a/crypto/blake2/m_blake2b.c
+++ b/crypto/blake2/m_blake2b.c
@@ -49,7 +49,7 @@ static const EVP_MD blake2b_md = {
     final,
     NULL,
     NULL,
-    0,
+    BLAKE2B_BLOCKBYTES,
     sizeof(EVP_MD *) + sizeof(BLAKE2B_CTX),
 };
 
diff --git a/crypto/blake2/m_blake2s.c b/crypto/blake2/m_blake2s.c
index e6991848221afdd8aa615bba4c4f7a4867058bc0..3fbb232e056a101b56cf099ea12f6699bcf2f174 100644
--- a/crypto/blake2/m_blake2s.c
+++ b/crypto/blake2/m_blake2s.c
@@ -49,7 +49,7 @@ static const EVP_MD blake2s_md = {
     final,
     NULL,
     NULL,
-    0,
+    BLAKE2S_BLOCKBYTES,
     sizeof(EVP_MD *) + sizeof(BLAKE2S_CTX),
 };