diff --git a/sop-java-picocli/src/main/java/sop/cli/picocli/commands/VerifyCmd.java b/sop-java-picocli/src/main/java/sop/cli/picocli/commands/VerifyCmd.java
deleted file mode 100644
index d76bb37..0000000
--- a/sop-java-picocli/src/main/java/sop/cli/picocli/commands/VerifyCmd.java
+++ /dev/null
@@ -1,102 +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.Verification;
-import sop.cli.picocli.Print;
-import sop.cli.picocli.SopCLI;
-import sop.exception.SOPGPException;
-import sop.operation.DetachedVerify;
-
-import java.io.IOException;
-import java.io.InputStream;
-import java.util.ArrayList;
-import java.util.List;
-
-@CommandLine.Command(name = "verify",
-        resourceBundle = "msg_detached-verify",
-        exitCodeOnInvalidInput = SOPGPException.UnsupportedOption.EXIT_CODE)
-public class VerifyCmd extends AbstractSopCmd {
-
-    @CommandLine.Parameters(index = "0",
-            paramLabel = "SIGNATURE")
-    String signature;
-
-    @CommandLine.Parameters(index = "1..*",
-            arity = "1..*",
-            paramLabel = "CERT")
-    List<String> certificates = new ArrayList<>();
-
-    @CommandLine.Option(names = {"--not-before"},
-            paramLabel = "DATE")
-    String notBefore = "-";
-
-    @CommandLine.Option(names = {"--not-after"},
-            paramLabel = "DATE")
-    String notAfter = "now";
-
-    @Override
-    public void run() {
-        DetachedVerify detachedVerify = throwIfUnsupportedSubcommand(
-                SopCLI.getSop().detachedVerify(), "verify");
-
-        if (notAfter != null) {
-            try {
-                detachedVerify.notAfter(parseNotAfter(notAfter));
-            } catch (SOPGPException.UnsupportedOption unsupportedOption) {
-                String errorMsg = getMsg("sop.error.feature_support.option_not_supported", "--not-after");
-                throw new SOPGPException.UnsupportedOption(errorMsg, unsupportedOption);
-            }
-        }
-        if (notBefore != null) {
-            try {
-                detachedVerify.notBefore(parseNotBefore(notBefore));
-            } catch (SOPGPException.UnsupportedOption unsupportedOption) {
-                String errorMsg = getMsg("sop.error.feature_support.option_not_supported", "--not-before");
-                throw new SOPGPException.UnsupportedOption(errorMsg, unsupportedOption);
-            }
-        }
-
-        for (String certInput : certificates) {
-            try (InputStream certIn = getInput(certInput)) {
-                detachedVerify.cert(certIn);
-            } catch (IOException ioException) {
-                throw new RuntimeException(ioException);
-            } catch (SOPGPException.BadData badData) {
-                String errorMsg = getMsg("sop.error.input.not_a_certificate", certInput);
-                throw new SOPGPException.BadData(errorMsg, badData);
-            }
-        }
-
-        if (signature != null) {
-            try (InputStream sigIn = getInput(signature)) {
-                detachedVerify.signatures(sigIn);
-            } catch (IOException e) {
-                throw new RuntimeException(e);
-            } catch (SOPGPException.BadData badData) {
-                String errorMsg = getMsg("sop.error.input.not_a_signature", signature);
-                throw new SOPGPException.BadData(errorMsg, badData);
-            }
-        }
-
-        List<Verification> verifications;
-        try {
-            verifications = detachedVerify.data(System.in);
-        } catch (SOPGPException.NoSignature e) {
-            String errorMsg = getMsg("sop.error.runtime.no_verifiable_signature_found");
-            throw new SOPGPException.NoSignature(errorMsg, e);
-        } catch (IOException ioException) {
-            throw new RuntimeException(ioException);
-        } catch (SOPGPException.BadData badData) {
-            String errorMsg = getMsg("sop.error.input.stdin_not_a_message");
-            throw new SOPGPException.BadData(errorMsg, badData);
-        }
-
-        for (Verification verification : verifications) {
-            Print.outln(verification.toString());
-        }
-    }
-}
diff --git a/sop-java-picocli/src/main/kotlin/sop/cli/picocli/commands/VerifyCmd.kt b/sop-java-picocli/src/main/kotlin/sop/cli/picocli/commands/VerifyCmd.kt
new file mode 100644
index 0000000..ef27266
--- /dev/null
+++ b/sop-java-picocli/src/main/kotlin/sop/cli/picocli/commands/VerifyCmd.kt
@@ -0,0 +1,81 @@
+// SPDX-FileCopyrightText: 2023 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package sop.cli.picocli.commands
+
+import java.io.IOException
+import picocli.CommandLine.*
+import sop.cli.picocli.SopCLI
+import sop.exception.SOPGPException.*
+
+@Command(
+    name = "verify",
+    resourceBundle = "msg_detached-verify",
+    exitCodeOnInvalidInput = UnsupportedOption.EXIT_CODE)
+class VerifyCmd : AbstractSopCmd() {
+
+    @Parameters(index = "0", paramLabel = "SIGNATURE") lateinit var signature: String
+
+    @Parameters(index = "1..*", arity = "1..*", paramLabel = "CERT")
+    lateinit var certificates: List<String>
+
+    @Option(names = ["--not-before"], paramLabel = "DATE") var notBefore: String = "-"
+
+    @Option(names = ["--not-after"], paramLabel = "DATE") var notAfter: String = "now"
+
+    override fun run() {
+        val detachedVerify =
+            throwIfUnsupportedSubcommand(SopCLI.getSop().detachedVerify(), "verify")
+        try {
+            detachedVerify.notAfter(parseNotAfter(notAfter))
+        } catch (unsupportedOption: UnsupportedOption) {
+            val errorMsg = getMsg("sop.error.feature_support.option_not_supported", "--not-after")
+            throw UnsupportedOption(errorMsg, unsupportedOption)
+        }
+
+        try {
+            detachedVerify.notBefore(parseNotBefore(notBefore))
+        } catch (unsupportedOption: UnsupportedOption) {
+            val errorMsg = getMsg("sop.error.feature_support.option_not_supported", "--not-before")
+            throw UnsupportedOption(errorMsg, unsupportedOption)
+        }
+
+        for (certInput in certificates) {
+            try {
+                getInput(certInput).use { certIn -> detachedVerify.cert(certIn) }
+            } catch (ioException: IOException) {
+                throw RuntimeException(ioException)
+            } catch (badData: BadData) {
+                val errorMsg = getMsg("sop.error.input.not_a_certificate", certInput)
+                throw BadData(errorMsg, badData)
+            }
+        }
+
+        try {
+            getInput(signature).use { sigIn -> detachedVerify.signatures(sigIn) }
+        } catch (e: IOException) {
+            throw RuntimeException(e)
+        } catch (badData: BadData) {
+            val errorMsg = getMsg("sop.error.input.not_a_signature", signature)
+            throw BadData(errorMsg, badData)
+        }
+
+        val verifications =
+            try {
+                detachedVerify.data(System.`in`)
+            } catch (e: NoSignature) {
+                val errorMsg = getMsg("sop.error.runtime.no_verifiable_signature_found")
+                throw NoSignature(errorMsg, e)
+            } catch (ioException: IOException) {
+                throw RuntimeException(ioException)
+            } catch (badData: BadData) {
+                val errorMsg = getMsg("sop.error.input.stdin_not_a_message")
+                throw BadData(errorMsg, badData)
+            }
+
+        for (verification in verifications) {
+            println(verification.toString())
+        }
+    }
+}