diff --git a/blake2b.c b/blake2b.c
index 15df011904..26a2f9e082 100644
--- a/blake2b.c
+++ b/blake2b.c
@@ -131,6 +131,26 @@ int blake2b_Init( blake2b_state *S, size_t outlen )
   return blake2b_init_param( S, P );
 }
 
+int blake2b_InitPersonal( blake2b_state *S, size_t outlen, const void *personal )
+{
+  blake2b_param P[1];
+
+  if ( ( !outlen ) || ( outlen > BLAKE2B_OUTBYTES ) ) 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 );
+  store32( &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, BLAKE2B_PERSONALBYTES );
+  return blake2b_init_param( S, P );
+}
 
 int blake2b_InitKey( blake2b_state *S, size_t outlen, const void *key, size_t keylen )
 {
diff --git a/blake2b.h b/blake2b.h
index 772a5cfe44..1c067ee166 100644
--- a/blake2b.h
+++ b/blake2b.h
@@ -30,6 +30,7 @@ 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);
 int blake2b_InitKey(blake2b_state *S, size_t outlen, const void *key, size_t keylen);
 int blake2b_Update(blake2b_state *S, const void *pin, size_t inlen);
 int blake2b_Final(blake2b_state *S, void *out, size_t outlen);