diff --git a/crypto/pkcs8/pkcs8_x509.c b/crypto/pkcs8/pkcs8_x509.c
index f5dd5b4..f7b37e9 100644
--- a/crypto/pkcs8/pkcs8_x509.c
+++ b/crypto/pkcs8/pkcs8_x509.c
@@ -99,7 +99,7 @@
 
 IMPLEMENT_ASN1_FUNCTIONS_const(PKCS8_PRIV_KEY_INFO)
 
-EVP_PKEY *EVP_PKCS82PKEY(PKCS8_PRIV_KEY_INFO *p8) {
+EVP_PKEY *EVP_PKCS82PKEY(const PKCS8_PRIV_KEY_INFO *p8) {
   uint8_t *der = NULL;
   int der_len = i2d_PKCS8_PRIV_KEY_INFO(p8, &der);
   if (der_len < 0) {
@@ -120,7 +120,7 @@
   return ret;
 }
 
-PKCS8_PRIV_KEY_INFO *EVP_PKEY2PKCS8(EVP_PKEY *pkey) {
+PKCS8_PRIV_KEY_INFO *EVP_PKEY2PKCS8(const EVP_PKEY *pkey) {
   CBB cbb;
   uint8_t *der = NULL;
   size_t der_len;
diff --git a/include/openssl/x509.h b/include/openssl/x509.h
index b89be08..453fb0b 100644
--- a/include/openssl/x509.h
+++ b/include/openssl/x509.h
@@ -2240,8 +2240,19 @@
 
 DECLARE_ASN1_FUNCTIONS_const(PKCS8_PRIV_KEY_INFO)
 
-OPENSSL_EXPORT EVP_PKEY *EVP_PKCS82PKEY(PKCS8_PRIV_KEY_INFO *p8);
-OPENSSL_EXPORT PKCS8_PRIV_KEY_INFO *EVP_PKEY2PKCS8(EVP_PKEY *pkey);
+// EVP_PKCS82PKEY returns |p8| as a newly-allocated |EVP_PKEY|, or NULL if the
+// key was unsupported or could not be decoded. If non-NULL, the caller must
+// release the result with |EVP_PKEY_free| when done.
+//
+// Use |EVP_parse_private_key| instead.
+OPENSSL_EXPORT EVP_PKEY *EVP_PKCS82PKEY(const PKCS8_PRIV_KEY_INFO *p8);
+
+// EVP_PKEY2PKCS8 encodes |pkey| as a PKCS#8 PrivateKeyInfo (RFC 5208),
+// represented as a newly-allocated |PKCS8_PRIV_KEY_INFO|, or NULL on error. The
+// caller must release the result with |PKCS8_PRIV_KEY_INFO_free| when done.
+//
+// Use |EVP_marshal_private_key| instead.
+OPENSSL_EXPORT PKCS8_PRIV_KEY_INFO *EVP_PKEY2PKCS8(const EVP_PKEY *pkey);
 
 // X509_PUBKEY_set0_param sets |pub| to a key with AlgorithmIdentifier
 // determined by |obj|, |param_type|, and |param_value|, and an encoded