diff --git a/gson/src/test/java/com/google/gson/internal/LinkedHashTreeMapTest.java b/gson/src/test/java/com/google/gson/internal/LinkedHashTreeMapTest.java
index 2cc2b2b7..3075ab0f 100644
--- a/gson/src/test/java/com/google/gson/internal/LinkedHashTreeMapTest.java
+++ b/gson/src/test/java/com/google/gson/internal/LinkedHashTreeMapTest.java
@@ -65,6 +65,7 @@ public final class LinkedHashTreeMapTest extends TestCase {
     LinkedHashTreeMap<Object, String> map = new LinkedHashTreeMap<Object, String>();
     try {
       map.put(new Object(), "android");
+      fail();
     } catch (ClassCastException expected) {}
   }