diff --git a/sop-java-testfixtures/src/main/java/sop/testsuite/AbortOnUnsupportedOption.java b/sop-java-testfixtures/src/main/java/sop/testsuite/AbortOnUnsupportedOption.java
new file mode 100644
index 0000000..cbd0746
--- /dev/null
+++ b/sop-java-testfixtures/src/main/java/sop/testsuite/AbortOnUnsupportedOption.java
@@ -0,0 +1,18 @@
+// SPDX-FileCopyrightText: 2025 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package sop.testsuite;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Inherited;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Target(ElementType.TYPE)
+@Retention(RetentionPolicy.RUNTIME)
+@Inherited
+public @interface AbortOnUnsupportedOption {
+
+}
diff --git a/sop-java-testfixtures/src/main/java/sop/testsuite/AbortOnUnsupportedOptionExtension.java b/sop-java-testfixtures/src/main/java/sop/testsuite/AbortOnUnsupportedOptionExtension.java
new file mode 100644
index 0000000..0bf366d
--- /dev/null
+++ b/sop-java-testfixtures/src/main/java/sop/testsuite/AbortOnUnsupportedOptionExtension.java
@@ -0,0 +1,26 @@
+// SPDX-FileCopyrightText: 2025 Paul Schaub <vanitasvitae@fsfe.org>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package sop.testsuite;
+
+import org.junit.jupiter.api.extension.ExtensionContext;
+import org.junit.jupiter.api.extension.TestExecutionExceptionHandler;
+import sop.exception.SOPGPException;
+
+import java.lang.annotation.Annotation;
+
+import static org.junit.jupiter.api.Assumptions.assumeTrue;
+
+public class AbortOnUnsupportedOptionExtension implements TestExecutionExceptionHandler {
+
+    @Override
+    public void handleTestExecutionException(ExtensionContext extensionContext, Throwable throwable) throws Throwable {
+        Class<?> testClass = extensionContext.getRequiredTestClass();
+        Annotation annotation = testClass.getAnnotation(AbortOnUnsupportedOption.class);
+        if (annotation != null && throwable instanceof SOPGPException.UnsupportedOption) {
+            assumeTrue(false, "Test aborted due to: " + throwable.getMessage());
+        }
+        throw throwable;
+    }
+}
diff --git a/sop-java-testfixtures/src/main/kotlin/sop/testsuite/AbortOnUnsupportedOption.kt b/sop-java-testfixtures/src/main/kotlin/sop/testsuite/AbortOnUnsupportedOption.kt
deleted file mode 100644
index cf99671..0000000
--- a/sop-java-testfixtures/src/main/kotlin/sop/testsuite/AbortOnUnsupportedOption.kt
+++ /dev/null
@@ -1,12 +0,0 @@
-// SPDX-FileCopyrightText: 2024 Paul Schaub <vanitasvitae@fsfe.org>
-//
-// SPDX-License-Identifier: Apache-2.0
-
-package sop.testsuite
-
-import java.lang.annotation.Inherited
-
-@Target(AnnotationTarget.TYPE)
-@Retention(AnnotationRetention.RUNTIME)
-@Inherited
-annotation class AbortOnUnsupportedOption
diff --git a/sop-java-testfixtures/src/main/kotlin/sop/testsuite/AbortOnUnsupportedOptionExtension.kt b/sop-java-testfixtures/src/main/kotlin/sop/testsuite/AbortOnUnsupportedOptionExtension.kt
deleted file mode 100644
index 809c78f..0000000
--- a/sop-java-testfixtures/src/main/kotlin/sop/testsuite/AbortOnUnsupportedOptionExtension.kt
+++ /dev/null
@@ -1,21 +0,0 @@
-// SPDX-FileCopyrightText: 2024 Paul Schaub <vanitasvitae@fsfe.org>
-//
-// SPDX-License-Identifier: Apache-2.0
-
-package sop.testsuite
-
-import org.junit.jupiter.api.Assumptions
-import org.junit.jupiter.api.extension.ExtensionContext
-import org.junit.jupiter.api.extension.TestExecutionExceptionHandler
-import sop.exception.SOPGPException
-
-class AbortOnUnsupportedOptionExtension : TestExecutionExceptionHandler {
-    override fun handleTestExecutionException(context: ExtensionContext, throwable: Throwable) {
-        val testClass = context.requiredTestClass
-        val annotation = testClass.getAnnotation(AbortOnUnsupportedOption::class.java)
-        if (annotation != null && SOPGPException.UnsupportedOption::class.isInstance(throwable)) {
-            Assumptions.assumeTrue(false, "Test aborted due to: " + throwable.message)
-        }
-        throw throwable
-    }
-}