diff --git a/pgpainless-sop/src/test/java/org/pgpainless/sop/V5Test.java b/pgpainless-sop/src/test/java/org/pgpainless/sop/V5Test.java
new file mode 100644
index 00000000..1c766d72
--- /dev/null
+++ b/pgpainless-sop/src/test/java/org/pgpainless/sop/V5Test.java
@@ -0,0 +1,97 @@
+// SPDX-FileCopyrightText: 2024 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package org.pgpainless.sop;
+
+import org.junit.jupiter.api.Test;
+import sop.ByteArrayAndResult;
+import sop.DecryptionResult;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class V5Test
+{
+
+    private static final String KEY = "-----BEGIN PGP PRIVATE KEY BLOCK-----\n" +
+            "\n" +
+            "lGEFXJH05BYAAAAtCSsGAQQB2kcPAQEHQFhZlVcVVtwf+21xNQPX+ecMJJBL0MPd\n" +
+            "fj75iux+my8QAAAAAAAiAQCHZ1SnSUmWqxEsoI6facIVZQu6mph3cBFzzTvcm5lA\n" +
+            "Ng5ctBhlbW1hLmdvbGRtYW5AZXhhbXBsZS5uZXSIlgUTFggASCIhBRk0e8mHJGQC\n" +
+            "X5nfPsLgAA7ZiEiS4fez6kyUAJFZVptUBQJckfTkAhsDBQsJCAcCAyICAQYVCgkI\n" +
+            "CwIEFgIDAQIeBwIXgAAA9cAA/jiR3yMsZMeEQ40u6uzEoXa6UXeV/S3wwJAXRJy9\n" +
+            "M8s0AP9vuL/7AyTfFXwwzSjDnYmzS0qAhbLDQ643N+MXGBJ2BZxmBVyR9OQSAAAA\n" +
+            "MgorBgEEAZdVAQUBAQdA+nysrzml2UCweAqtpDuncSPlvrcBWKU0yfU0YvYWWAoD\n" +
+            "AQgHAAAAAAAiAP9OdAPppjU1WwpqjIItkxr+VPQRT8Zm/Riw7U3F6v3OiBFHiHoF\n" +
+            "GBYIACwiIQUZNHvJhyRkAl+Z3z7C4AAO2YhIkuH3s+pMlACRWVabVAUCXJH05AIb\n" +
+            "DAAAOSQBAP4BOOIR/sGLNMOfeb5fPs/02QMieoiSjIBnijhob2U5AQC+RtOHCHx7\n" +
+            "TcIYl5/Uyoi+FOvPLcNw4hOv2nwUzSSVAw==\n" +
+            "=IiS2\n" +
+            "-----END PGP PRIVATE KEY BLOCK-----\n";
+
+    private static final String CERT = "\n" +
+            "-----BEGIN PGP PUBLIC KEY BLOCK-----\n" +
+            "\n" +
+            "mDcFXJH05BYAAAAtCSsGAQQB2kcPAQEHQFhZlVcVVtwf+21xNQPX+ecMJJBL0MPd\n" +
+            "fj75iux+my8QtBhlbW1hLmdvbGRtYW5AZXhhbXBsZS5uZXSIlgUTFggASCIhBRk0\n" +
+            "e8mHJGQCX5nfPsLgAA7ZiEiS4fez6kyUAJFZVptUBQJckfTkAhsDBQsJCAcCAyIC\n" +
+            "AQYVCgkICwIEFgIDAQIeBwIXgAAA9cAA/jiR3yMsZMeEQ40u6uzEoXa6UXeV/S3w\n" +
+            "wJAXRJy9M8s0AP9vuL/7AyTfFXwwzSjDnYmzS0qAhbLDQ643N+MXGBJ2Bbg8BVyR\n" +
+            "9OQSAAAAMgorBgEEAZdVAQUBAQdA+nysrzml2UCweAqtpDuncSPlvrcBWKU0yfU0\n" +
+            "YvYWWAoDAQgHiHoFGBYIACwiIQUZNHvJhyRkAl+Z3z7C4AAO2YhIkuH3s+pMlACR\n" +
+            "WVabVAUCXJH05AIbDAAAOSQBAP4BOOIR/sGLNMOfeb5fPs/02QMieoiSjIBnijho\n" +
+            "b2U5AQC+RtOHCHx7TcIYl5/Uyoi+FOvPLcNw4hOv2nwUzSSVAw==\n" +
+            "=WYfO\n" +
+            "-----END PGP PUBLIC KEY BLOCK-----\n";
+
+
+    @Test
+    public void encryptDecryptRoundtrip() throws IOException {
+        SOPImpl sop = new SOPImpl();
+        byte[] msg = "Hello!".getBytes(StandardCharsets.UTF_8);
+        byte[] ciphertext = sop.encrypt()
+                .withCert(CERT.getBytes(StandardCharsets.UTF_8))
+                .signWith(KEY.getBytes(StandardCharsets.UTF_8))
+                .plaintext(msg)
+                .toByteArrayAndResult()
+                .getBytes();
+
+        ByteArrayAndResult<DecryptionResult> bytesAndResult = sop.decrypt()
+                .verifyWithCert(CERT.getBytes(StandardCharsets.UTF_8))
+                .withKey(KEY.getBytes(StandardCharsets.UTF_8))
+                .ciphertext(ciphertext)
+                .toByteArrayAndResult();
+        byte[] plaintext = bytesAndResult.getBytes();
+        DecryptionResult result = bytesAndResult.getResult();
+
+        assertArrayEquals(msg, plaintext);
+        assertFalse(result.getVerifications().isEmpty());
+    }
+
+    @Test
+    public void decryptMessageFromGPG() throws IOException {
+        String msg = "-----BEGIN PGP MESSAGE-----\n" +
+                "\n" +
+                "hF4D5FV8KwL/v0sSAQdAafQ8/zXGjQFVU0KAVrztae7K4Qt8OcwBplSV1SZgNn8w\n" +
+                "h0kuBcw8OZTNvTT9xuMqObq0CNsWChOcDK9G/RzI6rn0loa9QYWyldNvL50bUqoe\n" +
+                "1FMBCQIQZ79HHAZPmUiIXkhqVhKygmbm4DaXg+S6XZ1jPX6mzyeKlwDlNNrdFOll\n" +
+                "QCbxAoki+JQdyZuDkrNXcabydZ9UBLUhBzAqCoCZyFIusc4utA==\n" +
+                "=rwsk\n" +
+                "-----END PGP MESSAGE-----\n";
+        SOPImpl sop = new SOPImpl();
+        ByteArrayAndResult<DecryptionResult> bytesAndResult = sop.decrypt()
+                .withKey(KEY.getBytes(StandardCharsets.UTF_8))
+                .ciphertext(msg.getBytes(StandardCharsets.UTF_8))
+                .toByteArrayAndResult();
+        DecryptionResult result = bytesAndResult.getResult();
+        assertTrue(result.getVerifications().isEmpty()); // not signed
+
+        byte[] plaintext = bytesAndResult.getBytes();
+        assertArrayEquals("Hello World :)".getBytes(StandardCharsets.UTF_8), plaintext);
+    }
+}