diff --git a/sop-java/src/main/java/sop/util/UTF8Util.java b/sop-java/src/main/java/sop/util/UTF8Util.java
deleted file mode 100644
index 1b4941b..0000000
--- a/sop-java/src/main/java/sop/util/UTF8Util.java
+++ /dev/null
@@ -1,37 +0,0 @@
-// SPDX-FileCopyrightText: 2022 Paul Schaub <vanitasvitae@fsfe.org>
-//
-// SPDX-License-Identifier: Apache-2.0
-
-package sop.util;
-
-import java.nio.ByteBuffer;
-import java.nio.CharBuffer;
-import java.nio.charset.CharacterCodingException;
-import java.nio.charset.Charset;
-import java.nio.charset.CharsetDecoder;
-import java.nio.charset.CodingErrorAction;
-
-public class UTF8Util {
-
-    public static final Charset UTF8 = Charset.forName("UTF8");
-    private static final CharsetDecoder UTF8Decoder = UTF8
-            .newDecoder()
-            .onUnmappableCharacter(CodingErrorAction.REPORT)
-            .onMalformedInput(CodingErrorAction.REPORT);
-
-    /**
-     * Detect non-valid UTF8 data.
-     *
-     * @see <a href="https://stackoverflow.com/a/1471193">ante on StackOverflow</a>
-     * @param data utf-8 encoded bytes
-     *
-     * @return decoded string
-     * @throws CharacterCodingException if the input data does not resemble UTF8
-     */
-    public static String decodeUTF8(byte[] data)
-            throws CharacterCodingException {
-        ByteBuffer byteBuffer = ByteBuffer.wrap(data);
-        CharBuffer charBuffer = UTF8Decoder.decode(byteBuffer);
-        return charBuffer.toString();
-    }
-}
diff --git a/sop-java/src/main/java/sop/util/package-info.java b/sop-java/src/main/java/sop/util/package-info.java
deleted file mode 100644
index 3dd9fc1..0000000
--- a/sop-java/src/main/java/sop/util/package-info.java
+++ /dev/null
@@ -1,8 +0,0 @@
-// SPDX-FileCopyrightText: 2021 Paul Schaub <vanitasvitae@fsfe.org>
-//
-// SPDX-License-Identifier: Apache-2.0
-
-/**
- * Utility classes.
- */
-package sop.util;
diff --git a/sop-java/src/main/kotlin/sop/util/UTF8Util.kt b/sop-java/src/main/kotlin/sop/util/UTF8Util.kt
new file mode 100644
index 0000000..770f32c
--- /dev/null
+++ b/sop-java/src/main/kotlin/sop/util/UTF8Util.kt
@@ -0,0 +1,37 @@
+// SPDX-FileCopyrightText: 2023 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package sop.util
+
+import java.nio.ByteBuffer
+import java.nio.charset.Charset
+import java.nio.charset.CodingErrorAction
+
+class UTF8Util {
+    companion object {
+        @JvmField val UTF8: Charset = Charset.forName("UTF8")
+
+        @JvmStatic
+        private val UTF8Decoder =
+            UTF8.newDecoder()
+                .onUnmappableCharacter(CodingErrorAction.REPORT)
+                .onMalformedInput(CodingErrorAction.REPORT)
+
+        /**
+         * Detect non-valid UTF8 data.
+         *
+         * @param data utf-8 encoded bytes
+         * @return decoded string
+         * @throws CharacterCodingException if the input data does not resemble UTF8
+         * @see [ante on StackOverflow](https://stackoverflow.com/a/1471193)
+         */
+        @JvmStatic
+        @Throws(CharacterCodingException::class)
+        fun decodeUTF8(data: ByteArray): String {
+            val byteBuffer = ByteBuffer.wrap(data)
+            val charBuffer = UTF8Decoder.decode(byteBuffer)
+            return charBuffer.toString()
+        }
+    }
+}