diff --git a/org.eclipse.xtext.tests/src/org/eclipse/xtext/validation/AbstractValidatorTester.java b/org.eclipse.xtext.testing/src/org/eclipse/xtext/testing/validation/AbstractValidatorTester.java
similarity index 87%
rename from org.eclipse.xtext.tests/src/org/eclipse/xtext/validation/AbstractValidatorTester.java
rename to org.eclipse.xtext.testing/src/org/eclipse/xtext/testing/validation/AbstractValidatorTester.java
index 81dbb5a4824..67a53261937 100644
--- a/org.eclipse.xtext.tests/src/org/eclipse/xtext/validation/AbstractValidatorTester.java
+++ b/org.eclipse.xtext.testing/src/org/eclipse/xtext/testing/validation/AbstractValidatorTester.java
@@ -1,12 +1,12 @@
 /*******************************************************************************
- * Copyright (c) 2009 itemis AG (http://www.itemis.eu) and others.
+ * Copyright (c) 2023 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;
+package org.eclipse.xtext.testing.validation;
 
 import java.util.Map;
 
@@ -14,10 +14,11 @@
 import org.eclipse.emf.ecore.EDataType;
 import org.eclipse.emf.ecore.EObject;
 import org.eclipse.emf.ecore.util.Diagnostician;
-import org.eclipse.xtext.testing.validation.AssertableDiagnostics;
 
 /**
  * @author Moritz Eysholdt - Initial contribution and API
+ * 
+ * @since 2.34
  */
 public abstract class AbstractValidatorTester {
 
@@ -27,7 +28,7 @@ public AssertableDiagnostics validate(EDataType type, Object obj) {
 		Diagnostic d = diagnostician.validate(type, obj);
 		return new AssertableDiagnostics(d);
 	}
-	
+
 	public AssertableDiagnostics validate(EObject obj) {
 		Diagnostic d = diagnostician.validate(obj);
 		return new AssertableDiagnostics(d);
diff --git a/org.eclipse.xtext.tests/src/org/eclipse/xtext/validation/ValidatorTester.java b/org.eclipse.xtext.testing/src/org/eclipse/xtext/testing/validation/ValidatorTester.java
similarity index 89%
rename from org.eclipse.xtext.tests/src/org/eclipse/xtext/validation/ValidatorTester.java
rename to org.eclipse.xtext.testing/src/org/eclipse/xtext/testing/validation/ValidatorTester.java
index 34b49d16dd6..eeace790435 100644
--- a/org.eclipse.xtext.tests/src/org/eclipse/xtext/validation/ValidatorTester.java
+++ b/org.eclipse.xtext.testing/src/org/eclipse/xtext/testing/validation/ValidatorTester.java
@@ -1,12 +1,12 @@
 /*******************************************************************************
- * Copyright (c) 2009 itemis AG (http://www.itemis.eu) and others.
+ * Copyright (c) 2023 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;
+package org.eclipse.xtext.testing.validation;
 
 import org.eclipse.emf.common.util.BasicDiagnostic;
 import org.eclipse.emf.common.util.Diagnostic;
@@ -14,8 +14,10 @@
 import org.eclipse.emf.ecore.impl.EValidatorRegistryImpl;
 import org.eclipse.emf.ecore.util.Diagnostician;
 import org.eclipse.xtext.Constants;
-import org.eclipse.xtext.testing.validation.AssertableDiagnostics;
+import org.eclipse.xtext.validation.AbstractDeclarativeValidator;
 import org.eclipse.xtext.validation.AbstractDeclarativeValidator.State;
+import org.eclipse.xtext.validation.AbstractInjectableValidator;
+import org.eclipse.xtext.validation.EValidatorRegistrar;
 
 import com.google.inject.Inject;
 import com.google.inject.Injector;
@@ -25,6 +27,8 @@
 
 /**
  * @author Moritz Eysholdt - Initial contribution and API
+ * 
+ * @since 2.34
  */
 public class ValidatorTester<T extends AbstractDeclarativeValidator> extends AbstractValidatorTester {
 
@@ -37,7 +41,7 @@ public ValidatorTester(T validator, Injector injector) {
 			injector.getInstance(EValidatorRegistrar.class),
 			injector.getInstance(Key.get(String.class, Names.named(Constants.LANGUAGE_NAME))));
 	}
-	
+
 	@Inject
 	public ValidatorTester(T validator, EValidatorRegistrar registrar, @Named(Constants.LANGUAGE_NAME) final String languageName) {
 		this.validator = validator;
@@ -56,7 +60,7 @@ public java.util.Map<Object,Object> createDefaultContext() {
 		registrar.setRegistry(originalRegistry);
 		validatorCalled = false;
 	}
-	
+
 	public AssertableDiagnostics diagnose() {
 		if (!validatorCalled)
 			throw new IllegalStateException("You have to call validator() before you call diagnose()");
diff --git a/org.eclipse.xtext.tests/src/org/eclipse/xtext/validation/ValidatorTesterTest.java b/org.eclipse.xtext.tests/src/org/eclipse/xtext/validation/ValidatorTesterTest.java
index 1b8f053e18d..f8589168564 100644
--- a/org.eclipse.xtext.tests/src/org/eclipse/xtext/validation/ValidatorTesterTest.java
+++ b/org.eclipse.xtext.tests/src/org/eclipse/xtext/validation/ValidatorTesterTest.java
@@ -19,6 +19,7 @@
 import org.eclipse.emf.ecore.EcoreFactory;
 import org.eclipse.emf.ecore.EcorePackage;
 import org.eclipse.xtext.XtextStandaloneSetup;
+import org.eclipse.xtext.testing.validation.ValidatorTester;
 import org.eclipse.xtext.tests.AbstractXtextTests;
 import org.junit.Test;