diff --git a/blake2b.h b/blake2b.h
index 1b2656745d..1a43e92d1e 100644
--- a/blake2b.h
+++ b/blake2b.h
@@ -30,8 +30,8 @@ typedef struct __blake2b_state
 #define BLAKE2B_KEY_LENGTH     BLAKE2B_KEYBYTES
 
 int blake2b_Init(blake2b_state *S, size_t outlen);
-int blake2b_InitPersonal(blake2b_state *S, size_t outlen, const void *personal, size_t personal_len);
 int blake2b_InitKey(blake2b_state *S, size_t outlen, const void *key, size_t keylen);
+int blake2b_InitPersonal(blake2b_state *S, size_t outlen, const void *personal, size_t personal_len);
 int blake2b_Update(blake2b_state *S, const void *pin, size_t inlen);
 int blake2b_Final(blake2b_state *S, void *out, size_t outlen);
 
diff --git a/blake2s.c b/blake2s.c
index 636479b9b9..57435e7a15 100644
--- a/blake2s.c
+++ b/blake2s.c
@@ -126,6 +126,29 @@ int blake2s_Init( blake2s_state *S, size_t outlen )
   return blake2s_init_param( S, P );
 }
 
+int blake2s_InitPersonal( blake2s_state *S, size_t outlen, const void *personal, size_t personal_len)
+{
+  blake2s_param P[1];
+
+  if ( ( !outlen ) || ( outlen > BLAKE2S_OUTBYTES ) ) return -1;
+  if ( ( !personal ) || ( personal_len != BLAKE2S_PERSONALBYTES ) ) return -1;
+
+  P->digest_length = (uint8_t)outlen;
+  P->key_length    = 0;
+  P->fanout        = 1;
+  P->depth         = 1;
+  store32( &P->leaf_length, 0 );
+  store32( &P->node_offset, 0 );
+  store16( &P->xof_length, 0 );
+  P->node_depth    = 0;
+  P->inner_length  = 0;
+  /* memset(P->reserved, 0, sizeof(P->reserved) ); */
+  memset( P->salt,     0, sizeof( P->salt ) );
+  memcpy( P->personal, personal, BLAKE2S_PERSONALBYTES );
+  return blake2s_init_param( S, P );
+}
+
+
 int blake2s_InitKey( blake2s_state *S, size_t outlen, const void *key, size_t keylen )
 {
   blake2s_param P[1];
diff --git a/blake2s.h b/blake2s.h
index dd34bf1949..57991bc913 100644
--- a/blake2s.h
+++ b/blake2s.h
@@ -31,6 +31,7 @@ typedef struct __blake2s_state
 
 int blake2s_Init(blake2s_state *S, size_t outlen);
 int blake2s_InitKey(blake2s_state *S, size_t outlen, const void *key, size_t keylen);
+int blake2s_InitPersonal(blake2s_state *S, size_t outlen, const void *personal, size_t personal_len);
 int blake2s_Update(blake2s_state *S, const void *pin, size_t inlen);
 int blake2s_Final(blake2s_state *S, void *out, size_t outlen);