diff --git a/pgpainless-core/src/main/java/org/pgpainless/key/OpenPgpV5Fingerprint.java b/pgpainless-core/src/main/java/org/pgpainless/key/OpenPgpV5Fingerprint.java
deleted file mode 100644
index a0a3d1f4..00000000
--- a/pgpainless-core/src/main/java/org/pgpainless/key/OpenPgpV5Fingerprint.java
+++ /dev/null
@@ -1,58 +0,0 @@
-// SPDX-FileCopyrightText: 2022 Paul Schaub <vanitasvitae@fsfe.org>
-//
-// SPDX-License-Identifier: Apache-2.0
-
-package org.pgpainless.key;
-
-import javax.annotation.Nonnull;
-
-import org.bouncycastle.openpgp.PGPKeyRing;
-import org.bouncycastle.openpgp.PGPPublicKey;
-import org.bouncycastle.openpgp.PGPPublicKeyRing;
-import org.bouncycastle.openpgp.PGPSecretKey;
-import org.bouncycastle.openpgp.PGPSecretKeyRing;
-
-/**
- * This class represents a hex encoded, upper case OpenPGP v5 fingerprint.
- */
-public class OpenPgpV5Fingerprint extends _64DigitFingerprint {
-
-    /**
-     * Create an {@link OpenPgpV5Fingerprint}.
-     *
-     * @param fingerprint uppercase hexadecimal fingerprint of length 64
-     */
-    public OpenPgpV5Fingerprint(@Nonnull String fingerprint) {
-        super(fingerprint);
-    }
-
-    public OpenPgpV5Fingerprint(@Nonnull byte[] bytes) {
-        super(bytes);
-    }
-
-    public OpenPgpV5Fingerprint(@Nonnull PGPPublicKey key) {
-        super(key);
-    }
-
-    public OpenPgpV5Fingerprint(@Nonnull PGPSecretKey key) {
-        this(key.getPublicKey());
-    }
-
-    public OpenPgpV5Fingerprint(@Nonnull PGPPublicKeyRing ring) {
-        super(ring);
-    }
-
-    public OpenPgpV5Fingerprint(@Nonnull PGPSecretKeyRing ring) {
-        super(ring);
-    }
-
-    public OpenPgpV5Fingerprint(@Nonnull PGPKeyRing ring) {
-        super(ring);
-    }
-
-    @Override
-    public int getVersion() {
-        return 5;
-    }
-
-}
diff --git a/pgpainless-core/src/main/java/org/pgpainless/key/OpenPgpV5Fingerprint.kt b/pgpainless-core/src/main/java/org/pgpainless/key/OpenPgpV5Fingerprint.kt
new file mode 100644
index 00000000..b82a3482
--- /dev/null
+++ b/pgpainless-core/src/main/java/org/pgpainless/key/OpenPgpV5Fingerprint.kt
@@ -0,0 +1,25 @@
+// SPDX-FileCopyrightText: 2023 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package org.pgpainless.key
+
+import org.bouncycastle.openpgp.PGPKeyRing
+import org.bouncycastle.openpgp.PGPPublicKey
+import org.bouncycastle.openpgp.PGPSecretKey
+
+/**
+ * This class represents a hex encoded uppercase OpenPGP v5 fingerprint.
+ */
+class OpenPgpV5Fingerprint: _64DigitFingerprint {
+
+    constructor(fingerprint: String): super(fingerprint)
+    constructor(key: PGPPublicKey): super(key)
+    constructor(key: PGPSecretKey): super(key)
+    constructor(keys: PGPKeyRing): super(keys)
+    constructor(bytes: ByteArray): super(bytes)
+
+    override fun getVersion(): Int {
+        return 5
+    }
+}
\ No newline at end of file
diff --git a/pgpainless-core/src/main/java/org/pgpainless/key/OpenPgpV6Fingerprint.java b/pgpainless-core/src/main/java/org/pgpainless/key/OpenPgpV6Fingerprint.java
deleted file mode 100644
index 79cc1715..00000000
--- a/pgpainless-core/src/main/java/org/pgpainless/key/OpenPgpV6Fingerprint.java
+++ /dev/null
@@ -1,58 +0,0 @@
-// SPDX-FileCopyrightText: 2023 Paul Schaub <vanitasvitae@fsfe.org>
-//
-// SPDX-License-Identifier: Apache-2.0
-
-package org.pgpainless.key;
-
-import javax.annotation.Nonnull;
-
-import org.bouncycastle.openpgp.PGPKeyRing;
-import org.bouncycastle.openpgp.PGPPublicKey;
-import org.bouncycastle.openpgp.PGPPublicKeyRing;
-import org.bouncycastle.openpgp.PGPSecretKey;
-import org.bouncycastle.openpgp.PGPSecretKeyRing;
-
-/**
- * This class represents a hex encoded, upper case OpenPGP v6 fingerprint.
- */
-public class OpenPgpV6Fingerprint extends _64DigitFingerprint {
-
-    /**
-     * Create an {@link OpenPgpV6Fingerprint}.
-     *
-     * @param fingerprint uppercase hexadecimal fingerprint of length 64
-     */
-    public OpenPgpV6Fingerprint(@Nonnull String fingerprint) {
-        super(fingerprint);
-    }
-
-    public OpenPgpV6Fingerprint(@Nonnull byte[] bytes) {
-        super(bytes);
-    }
-
-    public OpenPgpV6Fingerprint(@Nonnull PGPPublicKey key) {
-        super(key);
-    }
-
-    public OpenPgpV6Fingerprint(@Nonnull PGPSecretKey key) {
-        this(key.getPublicKey());
-    }
-
-    public OpenPgpV6Fingerprint(@Nonnull PGPPublicKeyRing ring) {
-        super(ring);
-    }
-
-    public OpenPgpV6Fingerprint(@Nonnull PGPSecretKeyRing ring) {
-        super(ring);
-    }
-
-    public OpenPgpV6Fingerprint(@Nonnull PGPKeyRing ring) {
-        super(ring);
-    }
-
-    @Override
-    public int getVersion() {
-        return 6;
-    }
-
-}
diff --git a/pgpainless-core/src/main/java/org/pgpainless/key/OpenPgpV6Fingerprint.kt b/pgpainless-core/src/main/java/org/pgpainless/key/OpenPgpV6Fingerprint.kt
new file mode 100644
index 00000000..11cf05b0
--- /dev/null
+++ b/pgpainless-core/src/main/java/org/pgpainless/key/OpenPgpV6Fingerprint.kt
@@ -0,0 +1,25 @@
+// SPDX-FileCopyrightText: 2023 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package org.pgpainless.key
+
+import org.bouncycastle.openpgp.PGPKeyRing
+import org.bouncycastle.openpgp.PGPPublicKey
+import org.bouncycastle.openpgp.PGPSecretKey
+
+/**
+ * This class represents a hex encoded, uppercase OpenPGP v6 fingerprint.
+ */
+class OpenPgpV6Fingerprint: _64DigitFingerprint {
+
+    constructor(fingerprint: String): super(fingerprint)
+    constructor(key: PGPPublicKey): super(key)
+    constructor(key: PGPSecretKey): super(key)
+    constructor(keys: PGPKeyRing): super(keys)
+    constructor(bytes: ByteArray): super(bytes)
+
+    override fun getVersion(): Int {
+        return 6
+    }
+}
\ No newline at end of file