diff --git a/library/src/main/java/com/google/maps/android/collections/MapObjectManager.java b/library/src/main/java/com/google/maps/android/collections/MapObjectManager.java
index 956c3b39c..4284a71bc 100644
--- a/library/src/main/java/com/google/maps/android/collections/MapObjectManager.java
+++ b/library/src/main/java/com/google/maps/android/collections/MapObjectManager.java
@@ -122,7 +122,7 @@ public void clear() {
         }
 
         protected java.util.Collection<O> getObjects() {
-            return Collections.unmodifiableCollection(mObjects);
+            return Collections.unmodifiableSet(mObjects);
         }
     }
 }