diff --git a/Libraries/LibWeb/Crypto/CryptoAlgorithms.cpp b/Libraries/LibWeb/Crypto/CryptoAlgorithms.cpp
index 6cce56120b6..578f7b60439 100644
--- a/Libraries/LibWeb/Crypto/CryptoAlgorithms.cpp
+++ b/Libraries/LibWeb/Crypto/CryptoAlgorithms.cpp
@@ -4507,10 +4507,14 @@ WebIDL::ExceptionOr<GC::Ref<JS::Object>> ED25519::export_key(Bindings::KeyFormat
         //    * Set the version field to 0.
         //    * Set the privateKeyAlgorithm field to a PrivateKeyAlgorithmIdentifier ASN.1 type with the following properties:
         //      * Set the algorithm object identifier to the id-Ed25519 OID defined in [RFC8410].
-        //    * Set the privateKey field to the result of DER-encoding a CurvePrivateKey ASN.1 type, as defined in Section 7 of [RFC8410], that represents the Ed25519 private key represented by the [[handle]] internal slot of key
+        //    * Set the privateKey field to the result of DER-encoding a CurvePrivateKey ASN.1 type,
+        //      as defined in Section 7 of [RFC8410], that represents the Ed25519 private key
+        //      represented by the [[handle]] internal slot of key
+        ::Crypto::ASN1::Encoder encoder;
+        TRY_OR_THROW_OOM(vm, encoder.write(key_data.bytes()));
 
         auto ed25519_oid = ::Crypto::ASN1::ed25519_oid;
-        auto data = TRY_OR_THROW_OOM(vm, ::Crypto::PK::wrap_in_private_key_info(key_data, ed25519_oid, nullptr));
+        auto data = TRY_OR_THROW_OOM(vm, ::Crypto::PK::wrap_in_private_key_info(encoder.finish(), ed25519_oid, nullptr));
 
         // 3. Let result be a new ArrayBuffer associated with the relevant global object of this [HTML], and containing data.
         return JS::ArrayBuffer::create(m_realm, move(data));