diff --git a/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/IntegrityProtectedInputStream.java b/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/IntegrityProtectedInputStream.java
deleted file mode 100644
index 37dcfca4..00000000
--- a/pgpainless-core/src/main/java/org/pgpainless/decryption_verification/IntegrityProtectedInputStream.java
+++ /dev/null
@@ -1,60 +0,0 @@
-// SPDX-FileCopyrightText: 2021 Paul Schaub <vanitasvitae@fsfe.org>
-//
-// SPDX-License-Identifier: Apache-2.0
-
-package org.pgpainless.decryption_verification;
-
-import java.io.IOException;
-import java.io.InputStream;
-import javax.annotation.Nonnull;
-
-import org.bouncycastle.openpgp.PGPEncryptedData;
-import org.bouncycastle.openpgp.PGPException;
-import org.pgpainless.exception.ModificationDetectionException;
-import org.slf4j.Logger;
-import org.slf4j.LoggerFactory;
-
-public class IntegrityProtectedInputStream extends InputStream {
-
-    private static final Logger LOGGER = LoggerFactory.getLogger(IntegrityProtectedInputStream.class);
-
-    private final InputStream inputStream;
-    private final PGPEncryptedData encryptedData;
-    private final ConsumerOptions options;
-    private boolean closed = false;
-
-    public IntegrityProtectedInputStream(InputStream inputStream, PGPEncryptedData encryptedData, ConsumerOptions options) {
-        this.inputStream = inputStream;
-        this.encryptedData = encryptedData;
-        this.options = options;
-    }
-
-    @Override
-    public int read() throws IOException {
-        return inputStream.read();
-    }
-
-    @Override
-    public int read(@Nonnull byte[] b, int offset, int length) throws IOException {
-        return inputStream.read(b, offset, length);
-    }
-
-    @Override
-    public void close() throws IOException {
-        if (closed) {
-            return;
-        }
-        closed = true;
-
-        if (encryptedData.isIntegrityProtected() && !options.isIgnoreMDCErrors()) {
-            try {
-                if (!encryptedData.verify()) {
-                    throw new ModificationDetectionException();
-                }
-                LOGGER.debug("Integrity Protection check passed");
-            } catch (PGPException e) {
-                throw new IOException("Data appears to not be integrity protected.", e);
-            }
-        }
-    }
-}
diff --git a/pgpainless-core/src/main/kotlin/org/pgpainless/decryption_verification/IntegrityProtectedInputStream.kt b/pgpainless-core/src/main/kotlin/org/pgpainless/decryption_verification/IntegrityProtectedInputStream.kt
new file mode 100644
index 00000000..a1e095f8
--- /dev/null
+++ b/pgpainless-core/src/main/kotlin/org/pgpainless/decryption_verification/IntegrityProtectedInputStream.kt
@@ -0,0 +1,42 @@
+// SPDX-FileCopyrightText: 2023 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package org.pgpainless.decryption_verification
+
+import org.bouncycastle.openpgp.PGPEncryptedData
+import org.bouncycastle.openpgp.PGPException
+import org.pgpainless.exception.ModificationDetectionException
+import org.slf4j.Logger
+import org.slf4j.LoggerFactory
+import java.io.IOException
+import java.io.InputStream
+
+class IntegrityProtectedInputStream(
+        private val inputStream: InputStream,
+        private val encryptedData: PGPEncryptedData,
+        private val options: ConsumerOptions
+) : InputStream() {
+    private var closed: Boolean = false
+
+    override fun read() = inputStream.read()
+    override fun read(b: ByteArray, off: Int, len: Int) = inputStream.read(b, off, len)
+    override fun close() {
+        if (closed) return
+
+        closed = true
+        if (encryptedData.isIntegrityProtected && !options.isIgnoreMDCErrors()) {
+            try {
+                if (!encryptedData.verify()) throw ModificationDetectionException()
+                LOGGER.debug("Integrity Protection check passed.")
+            } catch (e : PGPException) {
+                throw IOException("Data appears to not be integrity protected.", e)
+            }
+        }
+    }
+
+    companion object {
+        @JvmStatic
+        val LOGGER: Logger = LoggerFactory.getLogger(IntegrityProtectedInputStream::class.java)
+    }
+}
\ No newline at end of file