diff --git a/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/model/project/StandardProjectConfig.xtend b/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/model/project/StandardProjectConfig.xtend
index 64274d329..ddb1cbcb1 100644
--- a/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/model/project/StandardProjectConfig.xtend
+++ b/plugins/org.eclipse.xtext.xtext.generator/src/org/eclipse/xtext/xtext/generator/model/project/StandardProjectConfig.xtend
@@ -17,6 +17,7 @@ import org.eclipse.xtext.xtext.generator.Issues
 @Accessors
 class StandardProjectConfig extends XtextProjectConfig {
 
+	/** set to {@code true} by the project wizard(s) in case "Maven/Gradle" source layout is selected. */
 	boolean mavenLayout
 	boolean createEclipseMetaData
 	String rootPath
@@ -88,10 +89,19 @@ class StandardProjectConfig extends XtextProjectConfig {
 		rootPath + '/' + project.name
 	}
 
+	/**
+	 * In case of "Maven/Gradle" source layout the src outlet is named 'src/main/java',
+	 * test classes go into 'src/test/java' instead of any dedicated '...tests' project.
+	 */
 	protected def computeSrc(SubProjectConfig project) {
 		project.rootPath + '/' + if(mavenLayout) 'src/' + project.computeSourceSet + '/java' else 'src'
 	}
 
+	/**
+	 * In case of "Maven/Gradle" source layout the srcGen outlet is named 'src/main/xtext-gen',
+	 * test-related srcGen classes go into 'src/test/xtext-gen' instead of any dedicated '...tests' project.
+	 * Don't confuse it with 'src/main/xtend-gen'!
+	 */
 	protected def computeSrcGen(SubProjectConfig project) {
 		project.rootPath + '/' + if(mavenLayout) 'src/' + project.computeSourceSet + '/xtext-gen' else 'src-gen'
 	}
diff --git a/tests/org.eclipse.xtext.tests/.classpath b/tests/org.eclipse.xtext.tests/.classpath
index 8dedb7c92..aa9327a47 100644
--- a/tests/org.eclipse.xtext.tests/.classpath
+++ b/tests/org.eclipse.xtext.tests/.classpath
@@ -13,6 +13,11 @@
 			<attribute name="ignore_optional_problems" value="true"/>
 		</attributes>
 	</classpathentry>
+	<classpathentry kind="src" path="src-gen2">
+		<attributes>
+			<attribute name="ignore_optional_problems" value="true"/>
+		</attributes>
+	</classpathentry>
 	<classpathentry kind="src" path="xtend-gen"/>
 	<classpathentry kind="src" path="suites"/>
 	<classpathentry exported="true" kind="lib" path="lib/simple.jar"/>
diff --git a/tests/org.eclipse.xtext.tests/src/org/eclipse/xtext/GenerateAllTestLanguages2.mwe2 b/tests/org.eclipse.xtext.tests/src/org/eclipse/xtext/GenerateAllTestLanguages2.mwe2
index a2589edbb..21d134141 100644
--- a/tests/org.eclipse.xtext.tests/src/org/eclipse/xtext/GenerateAllTestLanguages2.mwe2
+++ b/tests/org.eclipse.xtext.tests/src/org/eclipse/xtext/GenerateAllTestLanguages2.mwe2
@@ -64,7 +64,7 @@ Workflow {
  * generated by Xtext
  */"
 			}
-			project = xtext.generator.model.project.StandardProjectConfig {
+			project = TestProjectConfig {
 				baseName = projectName
 				rootPath = ".."
 				runtime = {
@@ -90,9 +90,9 @@ Workflow {
 		language = TestLanguage {
 			name = "org.eclipse.xtext.generator.ecore.SuperTestLanguage"
 		}
-//		language = TestLanguage {
-//			name = "org.eclipse.xtext.generator.ecore.SubTestLanguage"
-//		}
+		language = TestLanguage {
+			name = "org.eclipse.xtext.generator.ecore.SubTestLanguage"
+		}
 //		language = TestLanguage {
 //			name = "org.eclipse.xtext.XtextGrammarTestLanguage"
 //		}
diff --git a/tests/org.eclipse.xtext.tests/src/org/eclipse/xtext/TestLanguage.xtend b/tests/org.eclipse.xtext.tests/src/org/eclipse/xtext/TestLanguage.xtend
index 60f59ab86..7b4a51c14 100644
--- a/tests/org.eclipse.xtext.tests/src/org/eclipse/xtext/TestLanguage.xtend
+++ b/tests/org.eclipse.xtext.tests/src/org/eclipse/xtext/TestLanguage.xtend
@@ -34,6 +34,9 @@ class TestLanguage extends XtextGeneratorLanguage {
 	EMFGeneratorFragment2 emfGenerator = new EMFGeneratorFragment2
 	XtextAntlrGeneratorFragment2 parserGenerator = new XtextAntlrGeneratorFragment2  => [
 		debugGrammar = true
+		options => [
+			classSplitting = true
+		]
 	]
 	XtextAntlrIDEAGeneratorFragment ideaParser = new XtextAntlrIDEAGeneratorFragment
 	
diff --git a/tests/org.eclipse.xtext.tests/src/org/eclipse/xtext/TestProjectConfig.xtend b/tests/org.eclipse.xtext.tests/src/org/eclipse/xtext/TestProjectConfig.xtend
new file mode 100644
index 000000000..7d069a5ba
--- /dev/null
+++ b/tests/org.eclipse.xtext.tests/src/org/eclipse/xtext/TestProjectConfig.xtend
@@ -0,0 +1,25 @@
+/*******************************************************************************
+ * Copyright (c) 2015 itemis AG (http://www.itemis.eu) and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *******************************************************************************/
+package org.eclipse.xtext
+
+import org.eclipse.xtext.xtext.generator.model.project.StandardProjectConfig
+import org.eclipse.xtext.xtext.generator.model.project.SubProjectConfig
+
+/**
+ * @author Christian Schneider - Initial contribution and API
+ */
+class TestProjectConfig extends StandardProjectConfig {
+	
+	/**
+	 * Put the 'srcGen' classes generated for those test languages that are migrated
+	 * to the new generator infrastructure into a separate source folder!
+	 */
+	override protected computeSrcGen(SubProjectConfig project) {
+		return super.computeSrcGen(project) + "2"
+	}
+}
\ No newline at end of file