diff --git a/pychunkedgraph/ingest/upgrade/parent_layer.py b/pychunkedgraph/ingest/upgrade/parent_layer.py
index 2869fcf8..a7e79b8f 100644
--- a/pychunkedgraph/ingest/upgrade/parent_layer.py
+++ b/pychunkedgraph/ingest/upgrade/parent_layer.py
@@ -51,7 +51,7 @@ def _get_cx_edges_at_timestamp(node, response, ts):
 
 
 def _populate_cx_edges_with_timestamps(
-    cg: ChunkedGraph, layer: int, nodes: list, earliest_ts
+    cg: ChunkedGraph, layer: int, nodes: list, nodes_ts:list, earliest_ts
 ):
     """
     Collect timestamps of edits from children, since we use the same timestamp
@@ -63,9 +63,10 @@ def _populate_cx_edges_with_timestamps(
     all_children = np.concatenate(list(CHILDREN.values()))
     response = cg.client.read_nodes(node_ids=all_children, properties=attrs)
     timestamps_d = get_parent_timestamps(cg, nodes)
-    for node in nodes:
+    for node, node_ts in zip(nodes, nodes_ts):
         CX_EDGES[node] = {}
         timestamps = timestamps_d[node]
+        timestamps.add(node_ts)
         for ts in sorted(timestamps):
             if ts < earliest_ts:
                 ts = earliest_ts
@@ -82,6 +83,7 @@ def update_cross_edges(cg: ChunkedGraph, layer, node, node_ts, earliest_ts) -> l
         try:
             cx_edges_d = CX_EDGES[node][node_ts]
         except KeyError:
+            print(CX_EDGES)
             raise KeyError(f"{node}:{node_ts}")
         edges = np.concatenate([empty_2d] + list(cx_edges_d.values()))
         if edges.size:
@@ -149,7 +151,7 @@ def update_chunk(
     nodes = list(CHILDREN.keys())
     random.shuffle(nodes)
     nodes_ts = cg.get_node_timestamps(nodes, return_numpy=False, normalize=True)
-    _populate_cx_edges_with_timestamps(cg, layer, nodes, earliest_ts)
+    _populate_cx_edges_with_timestamps(cg, layer, nodes, nodes_ts, earliest_ts)
 
     task_size = int(math.ceil(len(nodes) / mp.cpu_count() / 2))
     chunked_nodes = chunked(nodes, task_size)