diff --git a/gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/util/ExpandableStepIterator.java b/gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/util/ExpandableStepIterator.java
index 09e82d0..f5bd239 100644
--- a/gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/util/ExpandableStepIterator.java
+++ b/gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/traversal/step/util/ExpandableStepIterator.java
@@ -29,7 +29,7 @@
 /**
  * @author Marko A. Rodriguez (http://markorodriguez.com)
  */
-public final class ExpandableStepIterator<S> implements Iterator<Traverser.Admin<S>>, Serializable {
+public class ExpandableStepIterator<S> implements Iterator<Traverser.Admin<S>>, Serializable {
 
     private final TraverserSet<S> traverserSet = new TraverserSet<>();
     private final MultiIterator<Traverser.Admin<S>> traverserIterators = new MultiIterator<>();