diff --git a/OpenKeychain/src/test/java/org/sufficientlysecure/keychain/securitytoken/SecurityTokenConnectionCompatTest.java b/OpenKeychain/src/test/java/org/sufficientlysecure/keychain/securitytoken/SecurityTokenConnectionCompatTest.java
new file mode 100644
index 000000000..406ee6471
--- /dev/null
+++ b/OpenKeychain/src/test/java/org/sufficientlysecure/keychain/securitytoken/SecurityTokenConnectionCompatTest.java
@@ -0,0 +1,82 @@
+package org.sufficientlysecure.keychain.securitytoken;
+
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+import org.bouncycastle.util.encoders.Hex;
+import org.junit.Before;
+import org.junit.Ignore;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.sufficientlysecure.keychain.KeychainTestRunner;
+
+import static junit.framework.Assert.assertEquals;
+
+
+@RunWith(KeychainTestRunner.class)
+@Ignore("Only for reference right now")
+public class SecurityTokenConnectionCompatTest {
+    private byte[] encryptedSessionKey;
+    private OpenPgpCommandApduFactory openPgpCommandApduFactory;
+
+    @Before
+    public void setUp() throws Exception {
+        encryptedSessionKey = Hex.decode("07ff7b9ff36f70da1fe7a6b59168c24a7e5b48a938c4f970de46524a06ebf4a9175a9737cf2e6f30957110b31db70e9a2992401b1d5e99389f976356f4e3a28ff537362e7ce14b81200e21d4f0e77d46bd89f3a54ca06062289148a59387488ac01d30d2baf58e6b35e32434720473604a9f7d5083ca6d40e4a2dadedd68033a4d4bbdb06d075d6980c0c0ca19078dcdfb9d8cbcb34f28d0b968b6e09eda0e1d3ab6b251eb09f9fb9d9abfeaf9010001733b9015e9e4b6c9df61bbc76041f439d1273e41f5d0e8414a2b8d6d4c7e86f30b94cfba308b38de53d694a8ca15382301ace806c8237641b03525b3e3e8cbb017e251265229bcbb0da5d5aeb4eafbad9779");
+
+        openPgpCommandApduFactory = new OpenPgpCommandApduFactory();
+    }
+
+    /* we have a report of breaking compatibility on some earlier version.
+        this test checks what was sent in that version to what we send now.
+    // see https://github.com/open-keychain/open-keychain/issues/2049
+    // see https://github.com/open-keychain/open-keychain/commit/ee8cd3862f65de580ed949bc838628610e22cd98
+    */
+
+    @Test
+    public void testPrePostEquals() {
+        List<String> preApdus = decryptPre_ee8cd38();
+        List<String> postApdus = decryptNow();
+
+        assertEquals(preApdus, postApdus);
+    }
+
+    public List<String> decryptPre_ee8cd38() {
+        final int MAX_APDU_DATAFIELD_SIZE = 254;
+
+        int offset = 1; // Skip first byte
+        List<String> apduData = new ArrayList<>();
+
+        // Transmit
+        while (offset < encryptedSessionKey.length) {
+            boolean isLastCommand = offset + MAX_APDU_DATAFIELD_SIZE < encryptedSessionKey.length;
+            String cla = isLastCommand ? "10" : "00";
+
+            int len = Math.min(MAX_APDU_DATAFIELD_SIZE, encryptedSessionKey.length - offset);
+            apduData.add(cla + "2a8086" + Hex.toHexString(new byte[]{(byte) len})
+                    + Hex.toHexString(encryptedSessionKey, offset, len));
+
+            offset += MAX_APDU_DATAFIELD_SIZE;
+        }
+
+        return apduData;
+    }
+
+    public List<String> decryptNow() {
+        int mpiLength = ((((encryptedSessionKey[0] & 0xff) << 8) + (encryptedSessionKey[1] & 0xff)) + 7) / 8;
+        byte[] psoDecipherPayload = new byte[mpiLength + 1];
+        psoDecipherPayload[0] = (byte) 0x00;
+        System.arraycopy(encryptedSessionKey, 2, psoDecipherPayload, 1, mpiLength);
+
+        CommandApdu command = openPgpCommandApduFactory.createDecipherCommand(psoDecipherPayload);
+        List<CommandApdu> chainedApdus = openPgpCommandApduFactory.createChainedApdus(command);
+
+        List<String> apduData = new ArrayList<>();
+        for (CommandApdu chainCommand : chainedApdus) {
+            apduData.add(Hex.toHexString(chainCommand.toBytes()));
+        }
+
+        return apduData;
+    }
+}
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