diff --git a/openssl-sys/src/pem.rs b/openssl-sys/src/pem.rs
index a3d9cc6f3c03f7077b3d888e4c414dffd71a9d6e..978ec42da80add279c052f8ce7f4758107847044 100644
--- a/openssl-sys/src/pem.rs
+++ b/openssl-sys/src/pem.rs
@@ -66,6 +66,15 @@ const_ptr_api! {
         ) -> c_int;
         pub fn PEM_write_bio_PKCS7(bp: *mut BIO, x: #[const_ptr_if(ossl300)] PKCS7) -> c_int;
         pub fn PEM_write_bio_EC_PUBKEY(bp: *mut BIO, ec: #[const_ptr_if(ossl300)] EC_KEY) -> c_int;
+        pub fn i2d_PKCS8PrivateKey_bio(
+            bp: *mut BIO,
+            x: #[const_ptr_if(ossl300)] EVP_PKEY,
+            enc: *const EVP_CIPHER,
+            kstr: #[const_ptr_if(ossl300)] c_char,
+            klen: c_int,
+            cb: pem_password_cb,
+            u: *mut c_void,
+        ) -> c_int;
     }
 }
 
diff --git a/openssl/src/pkey.rs b/openssl/src/pkey.rs
index 2d443823de810f6baed7290c431cabae5fde4f43..581c9d19f3b8b25c6899389bbc7e1be8233fd6a8 100644
--- a/openssl/src/pkey.rs
+++ b/openssl/src/pkey.rs
@@ -49,13 +49,12 @@ use std::fmt;
 use std::mem;
 use std::ptr;
 
-use crate::bio::MemBioSlice;
+use crate::bio::{MemBio, MemBioSlice};
 use crate::dh::Dh;
 use crate::dsa::Dsa;
 use crate::ec::EcKey;
 use crate::error::ErrorStack;
 use crate::rsa::Rsa;
-#[cfg(ossl110)]
 use crate::symm::Cipher;
 use crate::util::{invoke_passwd_cb, CallbackState};
 use crate::{cvt, cvt_p};
@@ -684,6 +683,35 @@ impl PKey<Private> {
         }
     }
 
+    /// Serializes a private key into a DER-formatted PKCS#8, using the supplied password to
+    /// encrypt the key.
+    ///
+    /// # Panics
+    ///
+    /// Panics if `passphrase` contains an embedded null.
+    pub fn private_key_to_pkcs8_passphrase(
+        &self,
+        cipher: Cipher,
+        passphrase: &[u8],
+    ) -> Result<Vec<u8>, ErrorStack> {
+        unsafe {
+            let bio = MemBio::new()?;
+            let len = passphrase.len();
+            let passphrase = CString::new(passphrase).unwrap();
+            cvt(ffi::i2d_PKCS8PrivateKey_bio(
+                bio.as_ptr(),
+                self.as_ptr(),
+                cipher.as_ptr(),
+                passphrase.as_ptr() as *const _ as *mut _,
+                len as ::libc::c_int,
+                None,
+                ptr::null_mut(),
+            ))?;
+
+            Ok(bio.get_buf().to_owned())
+        }
+    }
+
     /// Creates a private key from its raw byte representation
     ///
     /// Algorithm types that support raw private keys are HMAC, X25519, ED25519, X448 or ED448
@@ -877,6 +905,17 @@ mod tests {
     fn test_encrypted_pkcs8_passphrase() {
         let key = include_bytes!("../test/pkcs8.der");
         PKey::private_key_from_pkcs8_passphrase(key, b"mypass").unwrap();
+
+        let rsa = Rsa::generate(2048).unwrap();
+        let pkey = PKey::from_rsa(rsa).unwrap();
+        let der = pkey
+            .private_key_to_pkcs8_passphrase(Cipher::aes_128_cbc(), b"mypass")
+            .unwrap();
+        let pkey2 = PKey::private_key_from_pkcs8_passphrase(&der, b"mypass").unwrap();
+        assert_eq!(
+            pkey.private_key_to_der().unwrap(),
+            pkey2.private_key_to_der().unwrap()
+        );
     }
 
     #[test]
diff --git a/systest/build.rs b/systest/build.rs
index 5cf20bc24e4768eb69e89c606a3b961b571b7f0d..5c905b428cad26ac959f2aeed644cef352f732ce 100644
--- a/systest/build.rs
+++ b/systest/build.rs
@@ -109,6 +109,7 @@ fn main() {
             s.starts_with("PEM_read_bio_") ||
             (s.starts_with("PEM_write_bio_") && s.ends_with("PrivateKey")) ||
             s == "d2i_PKCS8PrivateKey_bio" ||
+            s == "i2d_PKCS8PrivateKey_bio" ||
             s == "SSL_get_ex_new_index" ||
             s == "SSL_CTX_get_ex_new_index" ||
             s == "CRYPTO_get_ex_new_index"