diff --git a/pkcs8/tests/examples/bign256-priv.der b/pkcs8/tests/examples/bign256-priv.der
new file mode 100644
index 000000000..4b293bb76
Binary files /dev/null and b/pkcs8/tests/examples/bign256-priv.der differ
diff --git a/pkcs8/tests/examples/bign256-priv.pem b/pkcs8/tests/examples/bign256-priv.pem
new file mode 100644
index 000000000..e581587f5
--- /dev/null
+++ b/pkcs8/tests/examples/bign256-priv.pem
@@ -0,0 +1,4 @@
+-----BEGIN PRIVATE KEY-----
+MD8CAQAwGAYKKnAAAgAiZS0CAQYKKnAAAgAiZS0DAQQgH2a1uEtzOWdFM/AynHTy
+GDQoH+0HMkKeDHkjX8Jz4mk=
+-----END PRIVATE KEY-----
diff --git a/pkcs8/tests/private_key.rs b/pkcs8/tests/private_key.rs
index 1ef0f7361..a8333bcc5 100644
--- a/pkcs8/tests/private_key.rs
+++ b/pkcs8/tests/private_key.rs
@@ -13,6 +13,9 @@ use der::{pem::LineEnding, EncodePem};
 /// Elliptic Curve (P-256) PKCS#8 private key encoded as ASN.1 DER
 const EC_P256_DER_EXAMPLE: &[u8] = include_bytes!("examples/p256-priv.der");
 
+/// Elliptic Curve (Bign P-256) PKCS#8 private key encoded as ASN.1 DER
+const EC_BIGN_P256_DER_EXAMPLE: &[u8] = include_bytes!("examples/bign256-priv.der");
+
 /// Ed25519 PKCS#8 v1 private key encoded as ASN.1 DER
 const ED25519_DER_V1_EXAMPLE: &[u8] = include_bytes!("examples/ed25519-priv-pkcs8v1.der");
 
@@ -29,6 +32,9 @@ const X25519_DER_EXAMPLE: &[u8] = include_bytes!("examples/x25519-priv.der");
 #[cfg(feature = "pem")]
 const EC_P256_PEM_EXAMPLE: &str = include_str!("examples/p256-priv.pem");
 
+#[cfg(feature = "pem")]
+const EC_BIGN_P256_PEM_EXAMPLE: &str = include_str!("examples/bign256-priv.pem");
+
 /// Ed25519 PKCS#8 private key encoded as PEM
 #[cfg(feature = "pem")]
 const ED25519_PEM_V1_EXAMPLE: &str = include_str!("examples/ed25519-priv-pkcs8v1.pem");
@@ -62,6 +68,26 @@ fn decode_ec_p256_der() {
     assert_eq!(pk.private_key, &hex!("306B020101042069624171561A63340DE0E7D869F2A05492558E1A04868B6A9F854A866788188DA144034200041CACFFB55F2F2CEFD89D89EB374B2681152452802DEEA09916068137D839CF7FC481A44492304D7EF66AC117BEFE83A8D08F155F2B52F9F618DD447029048E0F")[..]);
 }
 
+#[test]
+fn decode_ec_bignp256_der() {
+    let pk = PrivateKeyInfo::try_from(EC_BIGN_P256_DER_EXAMPLE).unwrap();
+    assert_eq!(pk.version(), Version::V1);
+    assert_eq!(pk.algorithm.oid, "1.2.112.0.2.0.34.101.45.2.1".parse().unwrap());
+
+    assert_eq!(
+        pk.algorithm
+            .parameters
+            .unwrap()
+            .decode_as::<ObjectIdentifier>()
+            .unwrap(),
+        "1.2.112.0.2.0.34.101.45.3.1".parse().unwrap()
+    );
+
+    // Extracted with:
+    // $ openssl asn1parse -inform der -in tests/examples/bign256-priv.der
+    assert_eq!(pk.private_key, &hex!("1F66B5B84B7339674533F0329C74F21834281FED0732429E0C79235FC273E269"))
+}
+
 // Test vector from RFC8410 Section 10.3:
 // https://datatracker.ietf.org/doc/html/rfc8410#section-10.3
 #[test]
@@ -133,6 +159,14 @@ fn encode_ec_p256_der() {
     assert_eq!(EC_P256_DER_EXAMPLE, pk_encoded);
 }
 
+#[test]
+#[cfg(feature = "alloc")]
+fn encode_ec_bignp256_der() {
+    let pk = PrivateKeyInfo::try_from(EC_BIGN_P256_DER_EXAMPLE).unwrap();
+    let pk_encoded = pk.to_der().unwrap();
+    assert_eq!(EC_BIGN_P256_DER_EXAMPLE, pk_encoded);
+}
+
 #[test]
 #[cfg(feature = "alloc")]
 fn encode_ed25519_der_v1() {
@@ -165,6 +199,13 @@ fn encode_ec_p256_pem() {
     assert_eq!(EC_P256_PEM_EXAMPLE, pk.to_pem(LineEnding::LF).unwrap());
 }
 
+#[test]
+#[cfg(feature = "pem")]
+fn encode_ec_bignp256_pem() {
+    let pk = PrivateKeyInfo::try_from(EC_BIGN_P256_DER_EXAMPLE).unwrap();
+    assert_eq!(EC_BIGN_P256_PEM_EXAMPLE, pk.to_pem(LineEnding::LF).unwrap());
+}
+
 #[test]
 #[cfg(feature = "pem")]
 fn encode_ed25519_pem() {