diff --git a/sop-java-picocli/src/main/java/sop/cli/picocli/commands/InlineDetachCmd.java b/sop-java-picocli/src/main/java/sop/cli/picocli/commands/InlineDetachCmd.java
deleted file mode 100644
index 52b654f..0000000
--- a/sop-java-picocli/src/main/java/sop/cli/picocli/commands/InlineDetachCmd.java
+++ /dev/null
@@ -1,50 +0,0 @@
-// SPDX-FileCopyrightText: 2021 Paul Schaub <vanitasvitae@fsfe.org>
-//
-// SPDX-License-Identifier: Apache-2.0
-
-package sop.cli.picocli.commands;
-
-import picocli.CommandLine;
-import sop.Signatures;
-import sop.cli.picocli.SopCLI;
-import sop.exception.SOPGPException;
-import sop.operation.InlineDetach;
-
-import java.io.IOException;
-import java.io.OutputStream;
-
-@CommandLine.Command(name = "inline-detach",
-        resourceBundle = "msg_inline-detach",
-        exitCodeOnInvalidInput = SOPGPException.UnsupportedOption.EXIT_CODE)
-public class InlineDetachCmd extends AbstractSopCmd {
-
-    @CommandLine.Option(
-            names = {"--signatures-out"},
-            paramLabel = "SIGNATURES")
-    String signaturesOut;
-
-    @CommandLine.Option(names = "--no-armor",
-            negatable = true)
-    boolean armor = true;
-
-    @Override
-    public void run() {
-        InlineDetach inlineDetach = throwIfUnsupportedSubcommand(
-                SopCLI.getSop().inlineDetach(), "inline-detach");
-
-        throwIfOutputExists(signaturesOut);
-        throwIfMissingArg(signaturesOut, "--signatures-out");
-
-        if (!armor) {
-            inlineDetach.noArmor();
-        }
-
-        try (OutputStream outputStream = getOutput(signaturesOut)) {
-            Signatures signatures = inlineDetach
-                    .message(System.in).writeTo(System.out);
-            signatures.writeTo(outputStream);
-        } catch (IOException e) {
-            throw new RuntimeException(e);
-        }
-    }
-}
diff --git a/sop-java-picocli/src/main/kotlin/sop/cli/picocli/commands/InlineDetachCmd.kt b/sop-java-picocli/src/main/kotlin/sop/cli/picocli/commands/InlineDetachCmd.kt
new file mode 100644
index 0000000..e311adf
--- /dev/null
+++ b/sop-java-picocli/src/main/kotlin/sop/cli/picocli/commands/InlineDetachCmd.kt
@@ -0,0 +1,47 @@
+// SPDX-FileCopyrightText: 2023 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package sop.cli.picocli.commands
+
+import java.io.IOException
+import java.lang.RuntimeException
+import picocli.CommandLine.Command
+import picocli.CommandLine.Option
+import sop.cli.picocli.SopCLI
+import sop.exception.SOPGPException
+
+@Command(
+    name = "inline-detach",
+    resourceBundle = "msg_inline-detach",
+    exitCodeOnInvalidInput = SOPGPException.UnsupportedOption.EXIT_CODE)
+class InlineDetachCmd : AbstractSopCmd() {
+
+    @Option(names = ["--signatures-out"], paramLabel = "SIGNATURES")
+    var signaturesOut: String? = null
+
+    @Option(names = ["--no-armor"], negatable = true) var armor: Boolean = true
+
+    override fun run() {
+        val inlineDetach =
+            throwIfUnsupportedSubcommand(SopCLI.getSop().inlineDetach(), "inline-detach")
+
+        throwIfOutputExists(signaturesOut)
+        throwIfMissingArg(signaturesOut, "--signatures-out")
+
+        if (!armor) {
+            inlineDetach.noArmor()
+        }
+
+        try {
+            getOutput(signaturesOut).use { sigOut ->
+                inlineDetach
+                    .message(System.`in`)
+                    .writeTo(System.out) // message out
+                    .writeTo(sigOut) // signatures out
+            }
+        } catch (e: IOException) {
+            throw RuntimeException(e)
+        }
+    }
+}