diff --git a/org.eclipse.xtext.testing/src/org/eclipse/xtext/testing/extensions/InjectionExtension.java b/org.eclipse.xtext.testing/src/org/eclipse/xtext/testing/extensions/InjectionExtension.java
index c07e16e38..fbf75c17b 100644
--- a/org.eclipse.xtext.testing/src/org/eclipse/xtext/testing/extensions/InjectionExtension.java
+++ b/org.eclipse.xtext.testing/src/org/eclipse/xtext/testing/extensions/InjectionExtension.java
@@ -62,7 +62,7 @@ public class InjectionExtension implements BeforeEachCallback, AfterEachCallback
 
 		public RegistryReset(IRegistryConfigurator resetter) {
 			this.resetter = resetter;
-			resetter.setupRegistry();
+			setup();
 		}
 		
 		public void setup() {
diff --git a/org.eclipse.xtext.testlanguages/src/org/eclipse/xtext/testlanguages/fileAware/validation/FileAwareTestLanguageValidator.java b/org.eclipse.xtext.testlanguages/src/org/eclipse/xtext/testlanguages/fileAware/validation/FileAwareTestLanguageValidator.java
index dbf41624b..07aed6291 100644
--- a/org.eclipse.xtext.testlanguages/src/org/eclipse/xtext/testlanguages/fileAware/validation/FileAwareTestLanguageValidator.java
+++ b/org.eclipse.xtext.testlanguages/src/org/eclipse/xtext/testlanguages/fileAware/validation/FileAwareTestLanguageValidator.java
@@ -3,23 +3,25 @@
  */
 package org.eclipse.xtext.testlanguages.fileAware.validation;
 
+import org.eclipse.xtext.testlanguages.fileAware.fileAware.Element;
+import org.eclipse.xtext.testlanguages.fileAware.fileAware.FileAwarePackage;
+import org.eclipse.xtext.validation.Check;
 
 /**
- * This class contains custom validation rules. 
+ * This class contains custom validation rules.
  *
- * See https://www.eclipse.org/Xtext/documentation/303_runtime_concepts.html#validation
+ * See
+ * https://www.eclipse.org/Xtext/documentation/303_runtime_concepts.html#validation
  */
 public class FileAwareTestLanguageValidator extends AbstractFileAwareTestLanguageValidator {
-	
-//	public static final INVALID_NAME = 'invalidName'
-//
-//	@Check
-//	public void checkGreetingStartsWithCapital(Greeting greeting) {
-//		if (!Character.isUpperCase(greeting.getName().charAt(0))) {
-//			warning("Name should start with a capital",
-//					FileAwareTestLanguagePackage.Literals.GREETING__NAME,
-//					INVALID_NAME);
-//		}
-//	}
-	
+
+	public static final String INVALID_NAME = "invalidName";
+
+	@Check
+	public void checkGreetingStartsWithCapital(Element element) {
+		if ("LetItFail".equals(element.getName())) {
+			warning("LetItFail really is a bad name!", FileAwarePackage.Literals.ELEMENT__NAME, INVALID_NAME);
+		}
+	}
+
 }
diff --git a/org.eclipse.xtext.tests/build.gradle b/org.eclipse.xtext.tests/build.gradle
index f03ae0f15..f5294810c 100644
--- a/org.eclipse.xtext.tests/build.gradle
+++ b/org.eclipse.xtext.tests/build.gradle
@@ -13,6 +13,12 @@ dependencies {
 	// The MWE2 workflow depends on emf-gen, so we have to include it in the test dependencies
 	testCompile sourceSets.mwe2.output
 	testCompile 'args4j:args4j'
+	// optional for the utilities but mandatory to run the tests
+	testImplementation 'junit:junit'
+	testImplementation 'org.junit.jupiter:junit-jupiter-api'
+	testImplementation 'org.junit.jupiter:junit-jupiter-engine'
+	testImplementation 'org.junit.platform:junit-platform-suite-api'
+	testImplementation 'org.junit.platform:junit-platform-runner'
 }
 
 sourceSets.test {
diff --git a/org.eclipse.xtext.tests/src/org/eclipse/xtext/junit5/RunSuiteJUnit5.java b/org.eclipse.xtext.tests/src/org/eclipse/xtext/junit5/RunSuiteJUnit5.java
new file mode 100644
index 000000000..e79d8a792
--- /dev/null
+++ b/org.eclipse.xtext.tests/src/org/eclipse/xtext/junit5/RunSuiteJUnit5.java
@@ -0,0 +1,17 @@
+package org.eclipse.xtext.junit5;
+
+import org.junit.platform.runner.JUnitPlatform;
+import org.junit.platform.suite.api.SelectPackages;
+import org.junit.platform.suite.api.UseTechnicalNames;
+import org.junit.runner.RunWith;
+
+/**
+ * Test suite that will pick up all Junit5 tests from the listed package and run them
+ * when the suite is executed with Junit4.
+ */
+@RunWith(JUnitPlatform.class)
+@UseTechnicalNames
+@SelectPackages("org.eclipse.xtext.validation.junit5")
+public class RunSuiteJUnit5 {
+
+}
diff --git a/org.eclipse.xtext.tests/src/org/eclipse/xtext/validation/junit5/FileAwareTestLanguageValidationJunit5Test.java b/org.eclipse.xtext.tests/src/org/eclipse/xtext/validation/junit5/FileAwareTestLanguageValidationJunit5Test.java
new file mode 100644
index 000000000..1cf79b3d3
--- /dev/null
+++ b/org.eclipse.xtext.tests/src/org/eclipse/xtext/validation/junit5/FileAwareTestLanguageValidationJunit5Test.java
@@ -0,0 +1,50 @@
+/*******************************************************************************
+ * Copyright (c) 2020 itemis AG (http://www.itemis.eu) and others.
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0.
+ * 
+ * SPDX-License-Identifier: EPL-2.0
+ *******************************************************************************/
+package org.eclipse.xtext.validation.junit5;
+
+import org.eclipse.xtext.testing.InjectWith;
+import org.eclipse.xtext.testing.extensions.InjectionExtension;
+import org.eclipse.xtext.testing.util.ParseHelper;
+import org.eclipse.xtext.testing.validation.ValidationTestHelper;
+import org.eclipse.xtext.testlanguages.fileAware.fileAware.FileAwarePackage;
+import org.eclipse.xtext.testlanguages.fileAware.fileAware.PackageDeclaration;
+import org.eclipse.xtext.testlanguages.fileAware.tests.FileAwareTestLanguageInjectorProvider;
+import org.eclipse.xtext.testlanguages.fileAware.validation.FileAwareTestLanguageValidator;
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.extension.ExtendWith;
+
+import com.google.inject.Inject;
+
+/**
+ * @author cdietrich - Initial contribution and API
+ */
+@ExtendWith(InjectionExtension.class)
+@InjectWith(FileAwareTestLanguageInjectorProvider.class)
+public class FileAwareTestLanguageValidationJunit5Test {
+
+	@Inject
+	private ParseHelper<PackageDeclaration> parseHelper;
+
+	@Inject
+	private ValidationTestHelper validationTestHelper;
+
+	@Test
+	public void testWithJunit5_01() throws Exception {
+		PackageDeclaration model = parseHelper.parse("package x element Y {}");
+		validationTestHelper.assertNoIssues(model);
+	}
+
+	@Test
+	public void testWithJunit5_02() throws Exception {
+		PackageDeclaration model = parseHelper.parse("package x element LetItFail {}");
+		validationTestHelper.assertWarning(model.eResource(), FileAwarePackage.Literals.ELEMENT,
+				FileAwareTestLanguageValidator.INVALID_NAME);
+	}
+
+}