diff --git a/plugins/org.eclipse.xtext.util/.classpath b/plugins/org.eclipse.xtext.util/.classpath
index ad32c83a7..c72d35a04 100644
--- a/plugins/org.eclipse.xtext.util/.classpath
+++ b/plugins/org.eclipse.xtext.util/.classpath
@@ -3,5 +3,5 @@
 	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-1.6"/>
 	<classpathentry kind="con" path="org.eclipse.pde.core.requiredPlugins"/>
 	<classpathentry kind="src" path="src"/>
-	<classpathentry kind="output" path="bin"/>
+	<classpathentry kind="output" path="target/classes"/>
 </classpath>
diff --git a/plugins/org.eclipse.xtext.util/src/org/eclipse/xtext/util/Files.java b/plugins/org.eclipse.xtext.util/src/org/eclipse/xtext/util/Files.java
index 8ffe0998c..6b9e3b78d 100644
--- a/plugins/org.eclipse.xtext.util/src/org/eclipse/xtext/util/Files.java
+++ b/plugins/org.eclipse.xtext.util/src/org/eclipse/xtext/util/Files.java
@@ -68,7 +68,7 @@ public class Files {
 		}
 	}
 
-	public static boolean cleanFolder(File parentFolder, final FileFilter filter, boolean continueOnError,
+	public static boolean cleanFolder(final File parentFolder, final FileFilter filter, boolean continueOnError,
 			boolean deleteParentFolder) throws FileNotFoundException {
 		if (!parentFolder.exists()) {
 			throw new FileNotFoundException(parentFolder.getAbsolutePath());
@@ -83,6 +83,9 @@ public class Files {
 			};
 		log.debug("Cleaning folder " + parentFolder.toString());
 		final File[] contents = parentFolder.listFiles(myFilter);
+		if (contents == null) {
+			return true;
+		}
 		for (int j = 0; j < contents.length; j++) {
 			final File file = contents[j];
 			if (file.isDirectory()) {
@@ -97,7 +100,7 @@ public class Files {
 			}
 		}
 		if (deleteParentFolder) {
-			if (parentFolder.list().length==0 && !parentFolder.delete()) {
+			if (parentFolder.list() != null && parentFolder.list().length == 0 && !parentFolder.delete()) {
 				log.error("Couldn't delete " + parentFolder.getAbsolutePath());
 				return false;
 			}