diff --git a/crypto/siphash/siphash_ameth.c b/crypto/siphash/siphash_ameth.c
index d819461f8d..078eb543af 100644
--- a/crypto/siphash/siphash_ameth.c
+++ b/crypto/siphash/siphash_ameth.c
@@ -13,6 +13,7 @@
 #include "internal/asn1_int.h"
 #include "internal/siphash.h"
 #include "siphash_local.h"
+#include "internal/evp_int.h"
 
 /*
  * SIPHASH "ASN1" method. This is just here to indicate the maximum
@@ -46,6 +47,27 @@ static int siphash_pkey_public_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
     return ASN1_OCTET_STRING_cmp(EVP_PKEY_get0(a), EVP_PKEY_get0(b));
 }
 
+static int siphash_set_priv_key(EVP_PKEY *pkey, const unsigned char *priv,
+                                size_t len)
+{
+    ASN1_OCTET_STRING *os;
+
+    if (pkey->pkey.ptr != NULL || len != SIPHASH_KEY_SIZE)
+        return 0;
+
+    os = ASN1_OCTET_STRING_new();
+    if (os == NULL)
+        return 0;
+
+    if (!ASN1_OCTET_STRING_set(os, priv, len)) {
+        ASN1_OCTET_STRING_free(os);
+        return 0;
+    }
+
+    pkey->pkey.ptr = os;
+    return 1;
+}
+
 const EVP_PKEY_ASN1_METHOD siphash_asn1_meth = {
     EVP_PKEY_SIPHASH,
     EVP_PKEY_SIPHASH,
@@ -64,5 +86,17 @@ const EVP_PKEY_ASN1_METHOD siphash_asn1_meth = {
 
     siphash_key_free,
     siphash_pkey_ctrl,
-    0, 0
+    NULL,
+    NULL,
+
+    NULL,
+    NULL,
+    NULL,
+
+    NULL,
+    NULL,
+    NULL,
+
+    siphash_set_priv_key,
+    NULL,
 };