diff --git a/build-tools-internal/src/main/java/org/elasticsearch/gradle/internal/MrjarPlugin.java b/build-tools-internal/src/main/java/org/elasticsearch/gradle/internal/MrjarPlugin.java
index adf84b63d8689..9e2f44323f914 100644
--- a/build-tools-internal/src/main/java/org/elasticsearch/gradle/internal/MrjarPlugin.java
+++ b/build-tools-internal/src/main/java/org/elasticsearch/gradle/internal/MrjarPlugin.java
@@ -60,48 +60,30 @@ public void apply(Project project) {
         project.getPluginManager().apply(ElasticsearchJavaBasePlugin.class);
         var javaExtension = project.getExtensions().getByType(JavaPluginExtension.class);
 
-        var srcDir = project.getProjectDir().toPath().resolve("src");
-        List<Integer> mainVersions = new ArrayList<>();
-        try (var subdirStream = Files.list(srcDir)) {
-            for (Path sourceset : subdirStream.toList()) {
-                assert Files.isDirectory(sourceset);
-                String sourcesetName = sourceset.getFileName().toString();
-                Matcher sourcesetMatcher = MRJAR_SOURCESET_PATTERN.matcher(sourcesetName);
-                if (sourcesetMatcher.matches()) {
-                    mainVersions.add(Integer.parseInt(sourcesetMatcher.group(1)));
-                }
-            }
-        } catch (IOException e) {
-            throw new UncheckedIOException(e);
-        }
-
-        Collections.sort(mainVersions);
-        List<String> parentSourceSets = new ArrayList<>();
-        parentSourceSets.add(SourceSet.MAIN_SOURCE_SET_NAME);
+        List<Integer> mainVersions = findSourceVersions(project);
+        List<String> mainSourceSets = new ArrayList<>();
+        mainSourceSets.add(SourceSet.MAIN_SOURCE_SET_NAME);
+        List<String> testSourceSets = new ArrayList<>(mainSourceSets);
+        testSourceSets.add(SourceSet.TEST_SOURCE_SET_NAME);
         for (int javaVersion : mainVersions) {
-            String sourcesetName = "main" + javaVersion;
-            addMrjarSourceset(project, javaExtension, sourcesetName, parentSourceSets, javaVersion);
-            parentSourceSets.add(sourcesetName);
+            String mainSourceSetName = SourceSet.MAIN_SOURCE_SET_NAME + javaVersion;
+            SourceSet mainSourceSet = addSourceSet(project, javaExtension, mainSourceSetName, mainSourceSets, javaVersion);
+            configureSourceSetInJar(project, mainSourceSet, javaVersion);
+            mainSourceSets.add(mainSourceSetName);
+            testSourceSets.add(mainSourceSetName);
+
+            String testSourceSetName = SourceSet.TEST_SOURCE_SET_NAME + javaVersion;
+            SourceSet testSourceSet = addSourceSet(project, javaExtension, testSourceSetName, testSourceSets, javaVersion);
+            testSourceSets.add(testSourceSetName);
+            createTestTask(project, testSourceSet, javaVersion, mainSourceSets);
         }
-    }
 
-    private void addMrjarSourceset(
-        Project project,
-        JavaPluginExtension javaExtension,
-        String sourcesetName,
-        List<String> parentSourceSets,
-        int javaVersion
-    ) {
-        SourceSet sourceSet = javaExtension.getSourceSets().maybeCreate(sourcesetName);
-        for (String parentSourceSetName : parentSourceSets) {
-            GradleUtils.extendSourceSet(project, parentSourceSetName, sourcesetName);
-        }
+        configureMrjar(project);
+    }
 
+    private void configureMrjar(Project project) {
         var jarTask = project.getTasks().withType(Jar.class).named(JavaPlugin.JAR_TASK_NAME);
-        jarTask.configure(task -> {
-            task.into("META-INF/versions/" + javaVersion, copySpec -> copySpec.from(sourceSet.getOutput()));
-            task.manifest(manifest -> { manifest.attributes(Map.of("Multi-Release", "true")); });
-        });
+        jarTask.configure(task -> { task.manifest(manifest -> { manifest.attributes(Map.of("Multi-Release", "true")); }); });
 
         project.getTasks().withType(Test.class).named(JavaPlugin.TEST_TASK_NAME).configure(testTask -> {
             testTask.dependsOn(jarTask);
@@ -111,6 +93,19 @@ private void addMrjarSourceset(
             FileCollection testRuntime = sourceSets.getByName(SourceSet.TEST_SOURCE_SET_NAME).getRuntimeClasspath();
             testTask.setClasspath(testRuntime.minus(mainRuntime).plus(project.files(jarTask)));
         });
+    }
+
+    private SourceSet addSourceSet(
+        Project project,
+        JavaPluginExtension javaExtension,
+        String sourceSetName,
+        List<String> parentSourceSets,
+        int javaVersion
+    ) {
+        SourceSet sourceSet = javaExtension.getSourceSets().maybeCreate(sourceSetName);
+        for (String parentSourceSetName : parentSourceSets) {
+            GradleUtils.extendSourceSet(project, parentSourceSetName, sourceSetName);
+        }
 
         project.getTasks().withType(JavaCompile.class).named(sourceSet.getCompileJavaTaskName()).configure(compileTask -> {
             compileTask.getJavaCompiler()
@@ -132,6 +127,55 @@ private void addMrjarSourceset(
         project.getTasks().withType(CheckForbiddenApisTask.class).named(forbiddenApisTaskName).configure(forbiddenApisTask -> {
             forbiddenApisTask.setIgnoreMissingClasses(true);
         });
+
+        return sourceSet;
+    }
+
+    private void configureSourceSetInJar(Project project, SourceSet sourceSet, int javaVersion) {
+        var jarTask = project.getTasks().withType(Jar.class).named(JavaPlugin.JAR_TASK_NAME);
+        jarTask.configure(task -> task.into("META-INF/versions/" + javaVersion, copySpec -> copySpec.from(sourceSet.getOutput())));
+    }
+
+    private void createTestTask(Project project, SourceSet sourceSet, int javaVersion, List<String> mainSourceSets) {
+        var jarTask = project.getTasks().withType(Jar.class).named(JavaPlugin.JAR_TASK_NAME);
+        var testTaskProvider = project.getTasks().register(JavaPlugin.TEST_TASK_NAME + javaVersion, Test.class);
+        testTaskProvider.configure(testTask -> {
+            testTask.dependsOn(jarTask);
+
+            SourceSetContainer sourceSets = GradleUtils.getJavaSourceSets(project);
+            FileCollection testRuntime = sourceSet.getRuntimeClasspath();
+            for (String mainSourceSetName : mainSourceSets) {
+                FileCollection mainRuntime = sourceSets.getByName(mainSourceSetName).getOutput();
+                testRuntime = testRuntime.minus(mainRuntime);
+            }
+            testTask.setClasspath(testRuntime.plus(project.files(jarTask)));
+            testTask.setTestClassesDirs(sourceSet.getOutput().getClassesDirs());
+
+            testTask.getJavaLauncher()
+                .set(javaToolchains.launcherFor(spec -> spec.getLanguageVersion().set(JavaLanguageVersion.of(javaVersion))));
+        });
+
+        project.getTasks().named("check").configure(checkTask -> checkTask.dependsOn(testTaskProvider));
+    }
+
+    private static List<Integer> findSourceVersions(Project project) {
+        var srcDir = project.getProjectDir().toPath().resolve("src");
+        List<Integer> versions = new ArrayList<>();
+        try (var subdirStream = Files.list(srcDir)) {
+            for (Path sourceSetPath : subdirStream.toList()) {
+                assert Files.isDirectory(sourceSetPath);
+                String sourcesetName = sourceSetPath.getFileName().toString();
+                Matcher sourcesetMatcher = MRJAR_SOURCESET_PATTERN.matcher(sourcesetName);
+                if (sourcesetMatcher.matches()) {
+                    versions.add(Integer.parseInt(sourcesetMatcher.group(1)));
+                }
+            }
+        } catch (IOException e) {
+            throw new UncheckedIOException(e);
+        }
+
+        Collections.sort(versions);
+        return versions;
     }
 
     private static void stripPreviewFromFiles(Path compileDir) {