diff --git a/org.eclipse.xtext.ide.tests/.classpath b/org.eclipse.xtext.ide.tests/.classpath
index 1a09af3de..24d3d3142 100644
--- a/org.eclipse.xtext.ide.tests/.classpath
+++ b/org.eclipse.xtext.ide.tests/.classpath
@@ -9,6 +9,11 @@
 		</attributes>
 	</classpathentry>
 	<classpathentry including="**/*.java|**/*.xtend" kind="src" path="suites"/>
+	<classpathentry kind="src" path="src-gen">
+		<attributes>
+			<attribute name="ignore_optional_problems" value="true"/>
+		</attributes>
+	</classpathentry>
 	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-1.8/"/>
 	<classpathentry kind="con" path="org.eclipse.buildship.core.gradleclasspathcontainer"/>
 	<classpathentry kind="output" path="bin"/>
diff --git a/org.eclipse.xtext.testlanguages.ide/.classpath b/org.eclipse.xtext.testlanguages.ide/.classpath
index 15e616c69..f10cbac4b 100644
--- a/org.eclipse.xtext.testlanguages.ide/.classpath
+++ b/org.eclipse.xtext.testlanguages.ide/.classpath
@@ -1,7 +1,7 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <classpath>
 	<classpathentry kind="src" path="src"/>
-	<classpathentry kind="src" path="xtend-gen"/>
+	<classpathentry including="**/*.java|**/*.xtend" kind="src" path="xtend-gen"/>
 	<classpathentry kind="src" path="src-gen">
 		<attributes>
 			<attribute name="ignore_optional_problems" value="true"/>