diff --git a/src/pki_crypto.c b/src/pki_crypto.c
index 2aa0e956..a2c89325 100644
--- a/src/pki_crypto.c
+++ b/src/pki_crypto.c
@@ -662,7 +662,7 @@ ssh_string pki_private_key_to_pem(const ssh_key key,
             } else {
                 rc = PEM_write_bio_DSAPrivateKey(mem,
                                                  key->dsa,
-                                                 NULL, /* cipher */
+                                                 EVP_aes_128_cbc(),
                                                  NULL, /* kstr */
                                                  0, /* klen */
                                                  NULL, /* auth_fn */
@@ -687,7 +687,7 @@ ssh_string pki_private_key_to_pem(const ssh_key key,
             } else {
                 rc = PEM_write_bio_RSAPrivateKey(mem,
                                                  key->rsa,
-                                                 NULL, /* cipher */
+                                                 EVP_aes_128_cbc(),
                                                  NULL, /* kstr */
                                                  0, /* klen */
                                                  NULL, /* auth_fn */
@@ -712,7 +712,7 @@ ssh_string pki_private_key_to_pem(const ssh_key key,
             } else {
                 rc = PEM_write_bio_ECPrivateKey(mem,
                                                 key->ecdsa,
-                                                NULL, /* cipher */
+                                                EVP_aes_128_cbc(),
                                                 NULL, /* kstr */
                                                 0, /* klen */
                                                 NULL, /* auth_fn */
diff --git a/tests/unittests/torture_pki_dsa.c b/tests/unittests/torture_pki_dsa.c
index be428e0c..1bfdb894 100644
--- a/tests/unittests/torture_pki_dsa.c
+++ b/tests/unittests/torture_pki_dsa.c
@@ -81,7 +81,7 @@ static void torture_pki_dsa_write_privkey(void **state)
     unlink(LIBSSH_DSA_TESTKEY);
 
     rc = ssh_pki_export_privkey_file(origkey,
-                                     "",
+                                     NULL,
                                      NULL,
                                      NULL,
                                      LIBSSH_DSA_TESTKEY);
diff --git a/tests/unittests/torture_pki_ecdsa.c b/tests/unittests/torture_pki_ecdsa.c
index e7524b7a..18c5a78a 100644
--- a/tests/unittests/torture_pki_ecdsa.c
+++ b/tests/unittests/torture_pki_ecdsa.c
@@ -354,7 +354,7 @@ static void torture_pki_ecdsa_write_privkey(void **state)
     unlink(LIBSSH_ECDSA_TESTKEY);
 
     rc = ssh_pki_export_privkey_file(origkey,
-                                     "",
+                                     NULL,
                                      NULL,
                                      NULL,
                                      LIBSSH_ECDSA_TESTKEY);
diff --git a/tests/unittests/torture_pki_rsa.c b/tests/unittests/torture_pki_rsa.c
index 965ebcc3..b1dd97d0 100644
--- a/tests/unittests/torture_pki_rsa.c
+++ b/tests/unittests/torture_pki_rsa.c
@@ -434,7 +434,7 @@ static void torture_pki_rsa_write_privkey(void **state)
     unlink(LIBSSH_RSA_TESTKEY);
 
     rc = ssh_pki_export_privkey_file(origkey,
-                                     "",
+                                     NULL,
                                      NULL,
                                      NULL,
                                      LIBSSH_RSA_TESTKEY);