Index: oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/segment/SegmentNodeBuilder.java
===================================================================
--- oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/segment/SegmentNodeBuilder.java	(revision 1633110)
+++ oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/segment/SegmentNodeBuilder.java	(working copy)
@@ -47,6 +47,12 @@
         this.writer = writer;
     }
 
+    SegmentNodeBuilder(SegmentNodeBuilder parent, String name,
+            SegmentWriter writer) {
+        super(parent, name);
+        this.writer = writer;
+    }
+
     //-------------------------------------------------< MemoryNodeBuilder >--
 
     @Override
@@ -59,11 +65,11 @@
 
     //-------------------------------------------------------< NodeBuilder >--
 
-    @Override
-    public SegmentNodeState getBaseState() {
-        // guaranteed to be a SegmentNodeState
-        return (SegmentNodeState) super.getBaseState();
-    }
+//    @Override
+//    public SegmentNodeState getBaseState() {
+//        // guaranteed to be a SegmentNodeState
+//        return (SegmentNodeState) super.getBaseState();
+//    }
 
     @Override
     public SegmentNodeState getNodeState() {
@@ -76,4 +82,9 @@
         return sstate;
     }
 
+    @Override
+    protected MemoryNodeBuilder createChildBuilder(String name) {
+        return new SegmentNodeBuilder(this, name, writer);
+    }
+
 }
Index: oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/segment/SegmentNodeStore.java
===================================================================
--- oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/segment/SegmentNodeStore.java	(revision 1633110)
+++ oak-core/src/main/java/org/apache/jackrabbit/oak/plugins/segment/SegmentNodeStore.java	(working copy)
@@ -162,7 +162,7 @@
         SegmentNodeBuilder snb = (SegmentNodeBuilder) builder;
 
         NodeState root = getRoot();
-        SegmentNodeState before = snb.getBaseState();
+        NodeState before = snb.getBaseState();
         if (!fastEquals(before, root)) {
             SegmentNodeState after = snb.getNodeState();
             snb.reset(root);
@@ -307,7 +307,7 @@
 
         private final Random random = new Random();
 
-        private SegmentNodeState before;
+        private NodeState before;
 
         private SegmentNodeState after;
 
@@ -326,7 +326,7 @@
         }
 
         private boolean setHead(SegmentNodeBuilder builder) {
-            SegmentNodeState before = builder.getBaseState();
+            SegmentNodeState before = (SegmentNodeState) builder.getBaseState();
             SegmentNodeState after = builder.getNodeState();
 
             refreshHead();