diff --git a/src/main/java/com/commafeed/backend/service/FeedEntryFilteringService.java b/src/main/java/com/commafeed/backend/service/FeedEntryFilteringService.java
index 038d5393..bfb7d4ff 100644
--- a/src/main/java/com/commafeed/backend/service/FeedEntryFilteringService.java
+++ b/src/main/java/com/commafeed/backend/service/FeedEntryFilteringService.java
@@ -38,11 +38,6 @@ public class FeedEntryFilteringService {
 	private static JexlEngine initEngine() {
 		// classloader that prevents object creation
 		ClassLoader cl = new ClassLoader() {
-			@Override
-			public Class<?> loadClass(String name) throws ClassNotFoundException {
-				return null;
-			}
-
 			@Override
 			protected Class<?> loadClass(String name, boolean resolve) throws ClassNotFoundException {
 				return null;
diff --git a/src/test/java/com/commafeed/backend/service/FeedEntryFilteringServiceTest.java b/src/test/java/com/commafeed/backend/service/FeedEntryFilteringServiceTest.java
index 8babc731..8feda310 100644
--- a/src/test/java/com/commafeed/backend/service/FeedEntryFilteringServiceTest.java
+++ b/src/test/java/com/commafeed/backend/service/FeedEntryFilteringServiceTest.java
@@ -42,7 +42,7 @@ public class FeedEntryFilteringServiceTest {
 
 	@Test
 	public void simpleExpression() throws FeedEntryFilterException {
-		Assert.assertTrue(service.filterMatchesEntry("author eq 'athou'", entry));
+		Assert.assertTrue(service.filterMatchesEntry("author.toString() eq 'athou'", entry));
 	}
 
 	@Test(expected = FeedEntryFilterException.class)
@@ -67,8 +67,19 @@ public class FeedEntryFilteringServiceTest {
 
 	@Test
 	public void handlesNullCorrectly() throws FeedEntryFilterException {
+		entry.setUrl(null);
 		entry.setContent(new FeedEntryContent());
 		service.filterMatchesEntry("author eq 'athou'", entry);
 	}
 
+	@Test(expected = FeedEntryFilterException.class)
+	public void incorrectScriptThrowsException() throws FeedEntryFilterException {
+		service.filterMatchesEntry("aa eqz bb", entry);
+	}
+
+	@Test(expected = FeedEntryFilterException.class)
+	public void incorrectReturnTypeThrowsException() throws FeedEntryFilterException {
+		service.filterMatchesEntry("1", entry);
+	}
+
 }