diff --git a/phpseclib/Crypt/EC/Formats/Keys/PKCS8.php b/phpseclib/Crypt/EC/Formats/Keys/PKCS8.php
index 0ec7742f..7dab2193 100644
--- a/phpseclib/Crypt/EC/Formats/Keys/PKCS8.php
+++ b/phpseclib/Crypt/EC/Formats/Keys/PKCS8.php
@@ -129,12 +129,21 @@ abstract class PKCS8 extends Progenitor
         $components = [];
 
         if (isset($key['privateKey'])) {
-            $components['curve'] = $key['privateKeyAlgorithm']['algorithm'] == 'id-Ed25519' ? new Ed25519() : new Ed448();
-
-            // 0x04 == octet string
-            // 0x20 == length (32 bytes)
-            if (substr($key['privateKey'], 0, 2) != "\x04\x20") {
-                throw new \RuntimeException('The first two bytes of the private key field should be 0x0420');
+            if ($key['privateKeyAlgorithm']['algorithm'] == 'id-Ed25519') {
+                $components['curve'] = new Ed25519();
+                // 0x04 == octet string
+                // 0x20 == length (32 bytes)
+                if (substr($key['privateKey'], 0, 2) != "\x04\x20") {
+                    throw new \RuntimeException('The first two bytes of the Ed25519 private key field should be 0x0420');
+                }
+            } else {
+                // Assume Ed448
+                $components['curve'] = new Ed448();
+                // 0x04 == octet string
+                // 0x39 == length (57 bytes)
+                if (substr($key['privateKey'], 0, 2) != "\x04\x39") {
+                    throw new \RuntimeException('The first two bytes of the Ed448 private key field should be 0x0439');
+                }
             }
             $arr = $components['curve']->extractSecret(substr($key['privateKey'], 2));
             $components['dA'] = $arr['dA'];
@@ -207,13 +216,24 @@ abstract class PKCS8 extends Progenitor
         }
 
         if ($curve instanceof TwistedEdwardsCurve) {
-            return self::wrapPrivateKey(
-                "\x04\x20" . $secret,
-                [],
-                null,
-                $password,
-                $curve instanceof Ed25519 ? 'id-Ed25519' : 'id-Ed448'
-            );
+            if ($curve instanceof Ed25519) {
+                return self::wrapPrivateKey(
+                    "\x04\x20" . $secret,
+                    [],
+                    null,
+                    $password,
+                    'id-Ed25519'
+                );
+            } else {
+                // Assume Ed448
+                return self::wrapPrivateKey(
+                    "\x04\x39" . $secret,
+                    [],
+                    null,
+                    $password,
+                    'id-Ed448'
+                );
+            }
         }
 
         $publicKey = "\4" . $publicKey[0]->toBytes() . $publicKey[1]->toBytes();
diff --git a/tests/Unit/Crypt/EC/KeyTest.php b/tests/Unit/Crypt/EC/KeyTest.php
index adbb8f42..83ea2e8d 100644
--- a/tests/Unit/Crypt/EC/KeyTest.php
+++ b/tests/Unit/Crypt/EC/KeyTest.php
@@ -297,6 +297,33 @@ WEKBIQAZv0QJaYTN/oVBusFn3DuWyFCGqjC2tssMXDitcDFm4Q==
         $this->assertSameNL('Ed25519', $key->getPublicKey()->getCurve());
     }
 
+    // Generate with:
+    // openssl genpkey -algorithm ed448 | openssl ec -pubout
+    public function testEd448PublicKey()
+    {
+        $expected = '-----BEGIN PUBLIC KEY-----
+MEMwBQYDK2VxAzoAsA7zbld48IfDhm7Qd6FYrvnljtjhPRRqZi04NWyj8VXrWe1x
+BMLQFJEE0JDmKayUWpUWsRXwmb6A
+-----END PUBLIC KEY-----';
+        $key = PublicKeyLoader::load($expected);
+        $this->assertSameNL('Ed448', $key->getCurve());
+        $this->assertSameNL($expected, $key->toString('PKCS8'));
+    }
+
+    // Generate with:
+    // openssl genpkey -algorithm ed448
+    public function testEd448PrivateKey()
+    {
+        $expected = '-----BEGIN PRIVATE KEY-----
+MEcCAQAwBQYDK2VxBDsEOettXaJYob4hJNKJNOD+FfMvdesLKNp0KwochI6AKmAb
+tWhtkn99WOjd1PsGMh9zz2Vhdg3MwasOMQ==
+-----END PRIVATE KEY-----';
+        $key = PublicKeyLoader::load($expected);
+        $this->assertSameNL($expected, $key->toString('PKCS8'));
+        $this->assertSameNL('Ed448', $key->getCurve());
+        $this->assertSameNL('Ed448', $key->getPublicKey()->getCurve());
+    }
+
     public function testPuTTYnistp256()
     {
         $key = PublicKeyLoader::load($expected = 'PuTTY-User-Key-File-2: ecdsa-sha2-nistp256